Where to start?

So I am new to UE4 but experienced with C++. I have some friends wanting to start an FPS project and I figured I would start by creating a character with movement, working on camera (ADS and hip fire), etc. I just don’t know where to begin. Any advice?

I say you could try to get experience with blueprint as you work faster with it, and then combine it with c++ on specific task where you can get significant performance using c++ vs blueprint. You can watch vid a little bit long but worth it: Blueprints In-depth - Part 1 | Unreal Fest Europe 2019 | Unreal Engine - YouTube

For character movement, use the ContentExample project from epic and reverse engineering it character movement blueprint+blendspace for it fps char.
If you plan to do animation rig movement from scratch, the way i learn is from watching other game char movement, record and play on slow motion. Any small detail added to the rig will affect the way the char walk/run from blender to ue4 by a lot.
There no debugging on visual animation, so you would have to get skill on that such as changing speed, braking distance, acceleration, distance btw legs etc… affect movement visually.