Hi! You seem to be on the right path already
However, a few suggestions.
1) If you have any female friends, ask them for fashion tips. Hell, even watch Queer Eye on Netflix- it has some great, simple tips for fashion without being too hard or expensive to follow (also super fun to watch). Also, trying to replicate male celebrity styles are a good start too - just make sure its stuff you would actually wear.
2) Dear god do not approach every girl on your course. Not only does it seem desperate but every girl on the course will warn one another about you being the "creepy guy".
3) Self-improvement over the summer is great! Looking after your body is super important and getting into the habit of it now will make it easier when you're stressed out at uni.
4) Join clubs and societies you're interested in, both in and outside of uni. Its great for meeting people, improving your social skills and looking interesting on your CV.
5) Try dating apps like Tinder and Bumble. They can be superficial but you can get a genuine idea of how to interact with girls, and if (like me) you get nervous talking or don't feel interested anymore, you can unmatch and pretend it never happened lol.
6) Give it time. You're most likely not going to end up with a girlfriend within the first few weeks; everyone is getting used to everyone else and their new environment. Try and attend as many "freshers" events as possible, talk to lots of people. Anxiety is poopy but when you think about it, you may not even see the people again, but at least you were friendly to them. Also, people are just as nervous when it comes to dating and talking to strangers
.
7) Getting a job over the summer is a great idea; you'll have a little money to party and a little money to support yourself. Working in public service job like retail or catering is great because you can improve your social skills.
8) Try and stay as true to yourself as possible, don't be a clone of every dude around you. Yes, you can evolve and develop new interests, but don't become 'generic boy #383779'.
Good luck, from a gal also going to uni in September (hopefully, lol)!