Struggle with attempt to get into dating

As a 23M I’ve never gotten the chance to date anyone. For a long time I thought I was just gay, but recently thinking bisexual. Regardless, I’ve only asked two people out total and never have been asked out. First time asking out was ok, the rejection was straightforward and nothing bad really came of it. The second time basically traumatized me to the point I just don’t feel like even trying to ask anyone out. Thing is, I’m starting to find someone attractive at my new work but have no idea if she has any sort of similar feeling and just don’t want to go through the whole issue again that I had my most recent time.

(For those who may wonder) The second rejection was so terrible, and I’m not pinning it all on her, it was kind of both of us…. From being friends before, she conpeltely changed and started avoiding me, which made me wonder why, because all I did was ask, and it’s not like I said it in a creepy way or anything. Regardless, it made me constsntly want to seek the answer as to why she started doing as such, so I asked a few times but I just knew the answers were there to make me go away and so I just gave up and it was quite hard for me to deal with because I just never understood what was wrong.

I just don’t know how to approach repairing my mental state in this or how I should approach this new interest.