I was always told that if you’re building your very first machine, buy the core components from the same firm.
That way if something is screwy, it’s the firms job to help you fix it. Otherwise you’re not sure if it’s the ram, cpu or motherboard.
After you gain confidence and will have spare parts to self diagnose for future builds.
There is something really satisfying about doing your own build. Back in the day, used to be a side gig for something I enjoyed doing. Happy days.
You could just pick the parts (I’d suggest researching at least a little bit) and have someone check what you picked before committing, easy. Post them here too and people can give some better suggestions if necessary, with a reason why.
The building part is (usually, unless you go for an oddball case) easy, picking the parts is indeed tricky without a second pair of eyes if you’re new to this.