New User: Help with Fonts in Overleaf Template

If you compile using pdflatex, you have to go to iswthesis.sty and exchange lines 89–95

from

PassOptionsToPackage{osf,sc}{mathpazo}%
RequirePackage{mathpazo} % Palatino with real small caps and old style figures
usepackage{tgheros}
linespread{1.05} % a bit more for Palatino
PassOptionsToPackage{scaled=0.85}{DejaVuSansMon}%
RequirePackage{tgpagella}% bera monospace font
RequirePackage{textcomp}% declare missing symbols

to

% PassOptionsToPackage{osf,sc}{mathpazo}%
RequirePackage{ebgaramond-maths}
% RequirePackage{mathpazo} % Palatino with real small caps and old style figures
RequirePackage[scaled]{helvet}
linespread{1.05} % a bit more for Palatino
% PassOptionsToPackage{scaled=0.85}{DejaVuSansMon}%
RequirePackage{tgpagella}% bera monospace font
RequirePackage{textcomp}% declare missing symbols

For lualatex you need to have a look at lines 101–103:

    setsansfont{Tex Gyre Heros}
    setmainfont[Numbers=OldStyle]{TeX Gyre Pagella}
    setmonofont[Scale=0.85]{DejaVu Sans Mono}

Here you need to insert your system fonts: setsansfont{Helvetica Neue} or the version of Helvetica you've got installed in your system and setmainfont[Numbers=OldStyle]{EB Garamond} for Garamond.

Recompile and you're done!