Most every college has a process for examining a portfolio submission and awarding appropriate credit. As you look back at what you have already done, look over the courses you need. Do you feel competent you could pass a final exam in one of them? If your school offers challenge exams (take the final and pass, you get credit) you could go that route. If that isn't an option, build a portfolio and submit it to the school to be assessed for credit. Some schools have forms which must be included, so ask at advising first.
Think of a portfolio as a proof of your knowledge in the form of a project. You should use either a digital process which neatly presents your information or a physical method like a folder bound together to be read by faculty.
You will match a course from the catalog at your school, print or save the course outcomes. They will be included in the portfolio. This is your roadmap to matching the course to what you already know. Use the outcomes to address specifics in your knowledge, training and experience.
As an example, you want credit for an IT course, Introduction to Word Processing. You have trained at your local library and earned a certificate of completion. You will place the certificate in the portfolio. If your current job has you using Word every day to complete documents, you include your job description and years of experience with a letter from your HR department or supervisor stating this is what you do each day. If you have a Microsoft certification from taking the exam, include this certificate in the portfolio.
Each college accepts these in different manners. You may need to go to the cashier's office and pay a fee first, get a receipt and then drop off the portfolio in the department examining it. Again, your advisor will be able to give you the information if your college does not have a web page explaining it already.
Here are links to two schools portfolio pages:
https://www.waldenu.edu/online-bachelors-programs/resource/creating-an-undergraduate-prior-learning-portfolio
https://www.cmich.edu/academics/innovation-online/resources/credit-for-prior-learning/ugandg/forms-and-resources
These are typical of the process and fees. It can be a big time saver to those with significant experience outside of college.