Yes, you can go to the registrar’s office or the admissions office, and they will help you. Also, your high school counselor should be able to help you, too, even if you have already graduated.
Typically you need to get your high school to send the junior college a copy of your transcript (it costs $1 to do that at my daughter’s high school), you need to get copies of any tests like the ACT, the SAT, or the THEA that you took back in high school sent to the college, and then you need to fill out the college application. This may include a residency form that will determine what your fees will be.
Here in Texas, all instate public college and university applications are online at one site. You fill it out and tell the site what schools need to get a copy, and off it goes. In Texas, it is www.applytexas.org/. There may be something similar where you are.