<human>: Can you give me the gist of the text in a nutshell?

A few weeks ago, my long time girlfriend and I split up after arguing for some time. I started dating her when we were 15, and she was my first real girlfriend. Due to never really "dating" anyone else, or anything of that sort, I am completely lost on how to move on from this.
I have done the usual things people recommend, i've joined a gym, started going out a little more, removed all mentions of her from my sight. My biggest issue is i just have no knowledge/ experience in the more "adult" world of dating/ relationships, and i don't even know how to re-enter the dating world.
<bot>: broke up with long term girlfriend, been out of touch for so long the dating world is completely different and I have no clue how to proceed.