Reddit, how do I grow up?

Hey there reddit, I'm an 18-year college kid who has just finished his first year of college. A little bit about me, I'm a math major who wants to switch into biomedicial engineering and try to get into med school. Unfortunately, I'm a minority, and I really don't know a lot about how to get into med school and all that. Perhaps some medical redditors could point me in the right direction?

Also, I've never had a job, and I've never had a girlfriend. I would like to have both someday real soon, but I spend most of my time on the internet. I still feel like a little kid. How do I grow up? Where do I go to get some advice on this? I want to change for the better, but how do I do it?

Can anyone give me any advice? It doesn't have to be related to the things I mentioned here, just try to keep it relevant to the title question. Just advice. Thanks in advance!