Welcome to the forums,
@cocofigs! In my experience, cockatiels and budgies are one of the more successful interspecies pairings, and although it can never be guaranteed that any birds will get along, I think there's a good likelihood that your budgies would be accepting of a new 'tiel flockmate, and vice versa. Your potential 'tiel will need to have their own cage though, because as my (sadly now retired) avian vet always used to say, budgies often behave like that pesky little brother who always follows you around and gets right up in your face, and that certainly has always been the case with any budgie I've ever had! So your 'tiel will need their own space where they can retreat to for a little peace and quiet from time to time