Feats were such a HUGE part of 3.5e but seem to be much less powerful in 5e. Maybe it’s because of the proficiency bonus system that kind of improves everything you do. Either way, managing feats in DnDBeyond is pretty easy but not as apparent as things like skills and abilities. Easy to manage, but somewhat hidden.
The big area on the lower left of the character sheet has a bunch of cascading menus. Select Features & Traits, then Feats. All your selected feats will appear there.
Selecting Manage Feats will bring up that wonderful sidebar with every available feat listed. You can add or delete them with a click. You can also click the down arrow to bring up a description.
By default, you get 2 ability score points added every 4 levels. But you can forgo that and select a feat instead.
Curse of Strahd 