I assume u are talking about getting a better social circle, getting in to all the parties and being known as the guy to call and hang out with, and the one that all the girls want to date
Your first few weeks are important, everyone is new and getting to know each other.
1st be friendly w/ everyone and get everyones number.
*Get people together to go out.* Call up ppl that you think are cool and do stuff. Ex. movies, work-out, get somethin to eat, studyin, *parties*. If u get a bunch of ppl together to go to the movies, it social proofs you as the cool guy. Also, later on, ppl will invite you to do things w/ them to return the favor. This lets you meet more ppl.
Become friends with a lot of girls. DONT hit on them. There are sooo many girls out there. If you are a cool guy, they will introduce you to their friends and you get instant social proof. It makes things a lot easier. Also, some girls join sororities
After awhile, ppl will form groups that they hang out w/ 90% of the time. When, u have met some cool ppl, just start inviting the same ppl out over and over again. As they get comfortable around each-other, they will form a nice small group.
*Note*: One thing I have noticed is that u need a small group of ppl for them to get comfortable around each-other, somethin like 3-4 ppl. So you invite, say, just 3 ppl out w/ you to dinner. Start the conversations, then SHUT UP and let them talk and gain rapport.
I hope this helps, if u need more help/clarification PM me