do guys like being approached first

when i’m in public there are times where i found a guy attractive and wanting to strike up a conversation with them and i actually wanna know if they like being approached like that or not? or how do i approach them? do i just be front and ask for a number or an instagram handle? there once was a guy i met and he smiled at me and i could tell he was kinda shy but i was shy too so i decided to not do anything and i kinda regret not striking up a conversation… so yeah that leads to this question