Lingerie questions

Have bought 2 lingerie pieces one that is like a one piece swim suit and one that it's just a top that pushes the boobs but is loose in the tummy.

Ended up getting rid of the pushy boob and glory tummy because I didnt feel sexy in it.

I'm 19 so I'm new to this.

My boyfriend has never really shown interest in lingerie as far as I know but I've never really worn it around him so I want to try.

Just wondering like when to wear it, and like that's the process? With like the one piece it's not the easiest to take off, is that the point? Is it more of a look don't have sex with me but look how sexy I am?

Honestly no clue but wanna give it a shot please ideas