The best way to learn is to pick a project and build it.
There are lots of technologies to use, so my recommendation to just start building would be to use ViteJS, with React, and ESLint and Prettier. I might also recommend throwing TailwindCSS in there if it's not too much of a learning curve.
Theo recommends something a bit different that could also work: https://init.tips and https://init.tips/other
Apart from coding, I'd also recommend browsing sites like hacker news, twitter, and reddit. That, along with listening to podcasts or watching videos is a great way to get a better understanding of the frontend world.
https://developer.mozilla.org/
The holy grail of Javascript documentation. Use this over W3Schools.
https://beta.reactjs.org
The new react docs. Best to start here, but still a work in progress.
https://reactjs.org/docs
The old react docs. Still good but uses old class components in examples.
https://www.smashingmagazine.com
High quality articles on all sorts.
https://css-tricks.com
Great for all sorts of stuff on CSS. Covers pretty much everything.
https://blog.logrocket.com
Lots of articles posted all the time, but generally high quality
https://beta.reactjs.org/learn
The official react tutorial. Defs should be good enough to get you started.
https://reactforbeginners.com
Wes' course. Haven't done it but he's a good teacher.
https://wizardzines.com
Little tutorials on all sorts of stuff. Easy to understand.
https://github.com
Put all your code here. Work with public repositories.
https://www.npmtrends.com
Use this to compare npm packages. There's an art to picking packages that are well coded and maintained.
https://bundlejs.com
Check size of packages
https://www.typescriptlang.org
Typescript is typed javascript. Defs where things are heading. Compiles down to plain Javascript.
https://reactjs.org
The number one javascript library for building user interfaces. Used by 1/4 of websites or something.
https://vitejs.dev
The best bundler / runner / build tool. Use this over webpack.
https://eslint.org
A tool for linting javascript. Vite doesn't come with this so I'd recommend you set it up.
https://prettier.io
Auto formats code. Just use this for everything.
https://code.visualstudio.com
The best IDE for javascript. Best IDE for anything, probably. It's great.
https://tailwindcss.com
What I use for styling. Looks awkward at first but it just goes so well with component-based frameworks like react.
https://nextjs.org
Haven't used it much, but a lot of people recommend it to use with react.
https://remix.run
Another meta-framework like Next. Hearing good things about it.
https://www.netlify.com
Great and simple hosting
https://vercel.com/
Great and simple hosting
https://danluu.com
Really great stuff with deep dives and accessible writing. Don't let the lack of styling throw you off
https://www.joshwcomeau.com
Great introductory articles. Awesome visualizations.
http://paulgraham.com/articles.html Great articles on tech and life.
https://blog.codinghorror.com
Classic programming blog.
https://www.joelonsoftware.com
Also a classic.
https://overreacted.io
Dan Abramov's blog about React.js. Good for deep dives
https://podcasts.apple.com/au/podcast/syntax-tasty-web-development-treats/id1253186678
Really nice javascript focused podcast.
https://podcasts.apple.com/au/podcast/shoptalk/id493890455
Been around for ever, but still fresh and interesting.
https://podcasts.apple.com/au/podcast/modern-web/id1084236187
Great for beginners.
https://podcasts.apple.com/au/podcast/js-party-javascript-css-web-development/id1209616598
https://podcasts.apple.com/au/podcast/http-203/id1042283903
https://podcasts.apple.com/au/podcast/frontend-first/id1288274408
https://podcasts.apple.com/au/podcast/podrocket-a-web-development-podcast-from-logrocket/id1539945251
https://podcasts.apple.com/au/podcast/react-round-up/id1364741140
Other good podcasts.
https://news.ycombinator.com
Hacker News. Great for keeping on the pulse of everything.
https://www.reddit.com/r/programming/
https://www.reddit.com/r/javascript/
https://www.reddit.com/r/webdev/
https://www.reddit.com/r/web_design/
Some good reddit communities.
https://dev.to
A better medium.com, focused on developers.
There are lots of front end devs on twitter, and you should try to get on there if you want to stay really up to date with what's happening. Here's a list in no particular order:
https://twitter.com/dan_abramov
https://twitter.com/sarah_edo
https://twitter.com/kentcdodds
https://twitter.com/wesbos
https://twitter.com/meyerweb
https://twitter.com/jaffathecake
https://twitter.com/adamwathan
https://twitter.com/chriscoyier
https://twitter.com/laurieontech
https://twitter.com/acemarke
https://twitter.com/rwieruch
https://twitter.com/stolinski
https://twitter.com/ryanflorence
https://twitter.com/frontstuff_io
https://twitter.com/youyuxi
https://twitter.com/youyuxi
https://twitter.com/paulg
https://twitter.com/spolsky
https://twitter.com/codinghorror
https://twitter.com/threepointone
https://twitter.com/tylermcginnis
https://twitter.com/swyx
https://twitter.com/Rich_Harris
https://twitter.com/evanwallace
https://twitter.com/sindresorhus
https://twitter.com/JedWatson
https://twitter.com/tannerlinsley
https://twitter.com/b0rk
https://twitter.com/RyanCarniato
https://twitter.com/t3dotgg
https://twitter.com/mhevery
https://twitter.com/samselikoff
https://twitter.com/shanselman
https://twitter.com/antfu7
https://twitter.com/leeerob
https://twitter.com/benawad
https://www.youtube.com/c/Fireship
Great short videos explaining technologies.
https://www.youtube.com/c/SamSelikoff
Great explainer shorts.
https://www.youtube.com/c/TheoBrowne1017
Very opinionated videos, maybe more high level.
https://www.youtube.com/c/RyanCarniato9
Where the future is going. High level.
https://www.youtube.com/c/RealWorldReact
Some conference videos from the latest react conf.
https://www.youtube.com/c/TailwindLabs
Tailwind-specific videos. Great for learning css in general.
https://www.youtube.com/c/ArjanCodes
Python focused, but still good.
https://www.youtube.com/c/DanAbramov8
https://www.youtube.com/c/swyxTV
https://www.youtube.com/c/SteveSchoger
https://www.youtube.com/c/Simonswissdev
Some other good people.
https://discord.gg/aFafRsBh
Typescript - Great for getting help with Typescript.
https://discord.gg/7wVbAFmR
Reactiflux - Biggest react community.
https://discord.gg/kmq2PN3G
Theo's Discord.