How can I open myself up more to being in a romantic relationship?

At one time or another in my life, I have always found a reason to ignore being in a romantic relationship.

In middle and high school, I believed I was too young to take something like that seriously. I watched people my age get into them, and laughed at the idea that it was worthwhile then.

I had self-esteem and self-confidence issues then as well, something that still holds true at age 24. Only, with me being older, I'm not sure what are legitimate reasons to stay single and what aren't.

After being in therapy for some of those issues (including emotional struggles after being bullied during my teenage years and after losing a friend to suicide when I was 18), I am beginning to pay attention to my own needs. I realize that I would like to be in a relationship, among other things. Yet, I have doubts because I have - quite literally - no experience, I don't have a job, I've yet to finish college and still have the confidence/esteem problems.

I get that the only way I can gain experience is to try, but my past with this also plays a part in me holding back. I have only attempted to ask girls out a handful of times over the years, and have been rejected each time. As you might imagine, the rejection - combined with the other things I mentioned above - have made me quite hesitant despite my newfound desire.

With all of that on my plate... how do I not let my difficult past affect a possible relationship?