test.tex

\documentclass{memoir}

% Packete
\usepackage{fontspec} 

% Einstellungen
\setsecnumdepth{subsubsection}
\settocdepth{subsubsection}

\defaultfontfeatures[LexendDeca]
  {
    Extension = {.ttf},
    UprightFont = {*-Regular},
    AutoFakeBold,
    AutoFakeSlant,
    SmallCapsFeatures={Letters=SmallCaps}
  }


\setmainfont{LexendDeca}

% Extra-Befehle

% Dokumenten-Beginn
\begin{document}