Participate in Freshman orientation activities. If there's a dorm meeting or party, make an extra effort to go. Attend Freshman parties, gatherings, socials, etc. and introduce yourself to people. Everyone is in the same position is you. This is a new experience. If you need a conversation starter, start with that. Ask other freshmen what they think of the school, what they're majoring in, etc.
Get to know the people in your dorm. You will be living with these people all year, and chances are a few of them will become close friends. Invite them to go with you to an on-campus party, or bake cookies in the communal kitchen and go door-to-door, offering cookies as a welcome and get-to-know-you gift.
Start a conversation with someone every day that you don't know. If you're sitting in class, talk to the person next to you. Ask what they've heard about the professor or if they're going to that big on-campus party that weekend. If you're sitting on the bus, ask the person next to you their name. Strike up a conversation. This can help you meet new people and make new friends.
Join on-campus groups. On most college campuses, there are groups for every interest under the sun. Do your research and join groups that interest you. You'll be surprised of the plethora of resources and friends you'll find in these groups.