My recommendation for free Icon Sets that I have already used in many projects and like to come back to whenever a new project comes up.

Heroicons

Beautiful hand-crafted SVG icons, by the makers of Tailwind CSS.

heroicons.com


Phosphor Icons

Phosphor is a flexible icon family for interfaces, diagrams, presentations — whatever, really.

phosphoricons.com


Feather Icons

Simply beautiful open source icons.

feathericons.com