I won't duplicate what others have said, but in addition:
Font Awesome is still great, we have a pro license at work
Nucleo Icons for personal projects, I prefer them over FA actually, and their turnaround time for newly requested icons is much better
Codyhouse Framework for layouts, better support for modern browsers than Bootstrap like CSS Grid and Custom Properties, also smaller file size and more componentized, only use the CSS you need
I won't duplicate what others have said, but in addition: