I am in college at 59 years old. I also work full time.
I can tell you this.....there is no substitute for study and lots of it. Turn off the T.V. Leave the phone in another room, and read, read and read again. Get up early and read for an hour before breakfast if you are better at things in the a.m.
Also, most campuses have tutoring. I took Algebra, and after each class, I went to tutoring to do my homework. They were helpful to the extreme, and I know I couldn't have done it without them.
Make your goal good grades. Then let nothing stop you. You can do it...if you put in the work.