just eyeballin the specs it looks alright - like idrk if its all compatible I assume they are. I would get more ram if possible, I think 32 is gonna be the standard soon if not now (therefore if you want to future proof maybe get more).

Also get more fans. I've heard that there are noctua clones (or something else ) that have been doing well but I can remember the name.

Get a ups - dont want to have your computer fry during a storm.

Maybe increase powersupply because overtime they will lose there capability( I dont know what its called exactly but basically over time it will decrease in output).

Oh shit I just noticed, do you have a cpu cooler? DO NOT CHEAP OUT ON THIS. Im pretty sure ryzen7 doesnt come with a heatsink but if it does, chances are its mid. Ive only built with air coolers never tried AIO liquid coolers so I cant say much about them.

You "could" buy stuff used but like since this is your first pc I would try getting everything new. Also, new stuff "can" sometimes come outta the box broken (it just happens sometimes) so keep that in mind. But overall, yeah have fun :] I assume you are also getting a gaming monitor so make sure you set the refresh rate in os settings! Also dont plug in displayport or hdmi cable into motherboard. Sorry for the long text but again have fun!!

THERMAL PASTE- dont need to be too fancy but do shop around.

Also if you do end up getting more fans, you might need a fan controller. I do not know if your motherboard has enough fan ports. Do keep this in mind ~ it sucks to go back to a store to buy more stuff.