Make use of tools which help to save time and effort. This may mean using existing libraries and frameworks instead of looking to build things from scratch. For example, if you want to add a tab to your Teams application, search the web for HTML templates that are close to what you are looking for and modify them accordingly.
Assuming you are clear on what you want to build, go through the courses and resources in order to build what you want instead of doing them for their own sake. For example, instead of spending a 100 hours to complete a course and only then starting development, you can first pick out the portion that will give you enough knowledge to get started. You can then refer back to the materials and complement them as necessary. This will probably involve searching a lot of things up as you go along to help you understand everything that you need, and is part of the learning proces