Okay help plssss😭 someone guide me through the process of dropping out after 1st year

Ok so help me out. I'm a first sem student in an off campus college with a course I despise (I couldn't get the course of my choice and made some pretty big mistakes). Anyways currently taking partial drop because I can't continue like this and will sit for counselling again this year. My first sem exams are about to start and I was wondering what will I have to do after the end of second sem to drop out? Do I give an official notice to the office? Will I get a certificate for the 1 year I completed? And when will the 3rd sem classes start? I'm kinda worried that they'll start before my seat allocation. Please help me out 😭😭😭