How to write a pushover character

I'm trying to write a pushover, The character supposed to be smart but I kinda don't know how to balance that trait with naivete and gullible, also he supposed to be a social butterfly but he tends to not stand up for himself

Pushoverness could also be connected to being very laid-back in general? Like, he could be smart enough to know that people are taking advantage of him but he doesn't want to strain the relationship by calling them out on it. I know quite a few people like that irl

Ok thanks