Attend class. Though optional, attending helps you learn, ensures you hear key announcements, helps you find study partners and friends, and more. Serious, just go!

Study the syllabus. It's like a pseudo-contract, so know what you're responsible for. Only takes 10 min, time well spent. Review it mid-term and end-of-term too. 

Meet classmates. It's normal to talk with strangers in college (in high-school, not so much). Finding study partners can yield more success, plus it's more fun. Humans benefit from regular human contact.

Have a schedule. Plan your week, including study and rec time. You'll get more done, AND enjoy rec time more. 

Care for yourself. Exercise daily (even walking), sleep well, eat reasonably, and spend time with people in-person. All greatly improve mood, reduce anxiety and depression, and more. 

Try not to stress. Aim for good grades, but realize you'll win some and lose some; perfection isn't necessary. Things balance out. You'll be OK!!!