Stroller with compatible car seat

Michelle

Hi ladies! First time mom here and I’m 14 weeks. Silly question but are there strollers out there where you can get a universal car seat and piece for install? Or do you have to buy ones that are sold together with the stroller and car seat? Would love to get a used stroller but want a new car seat to ensure there were no accidents. This is all new to me! And if so what product do you like and why?