Ehm i have an 770 gtx but just bought hardware such as ryzen 5 5700x ,16gb ram, samsung 980pro ssd, 750watt power supply and a b550m motherboardWhat specifically do you mean by a "bad GPU?" This question is quite vague as worded.
thank you so muchSo you meant a 'cheap' GPU. It won't damage anything at all, it'll just create a bottleneck at most, nothing else. It's perfectly fine to use the GTX 770 and wait and save for a better one in the future! Best of luck!
Regards,
Asbaat
corsiar rm 750xThere is no need for concern. The idea hardware will damage something simply because potential isn't reached is missguided.
However, power supply wattage doesn't elaborate quality, that will be a concern if you bought some cheap psu claiming to be 750w.