Question about applying for a Masters Program in a different field of study

Hello everyone, back in 2015 I graduated with a bachelors in Business Administration; Information Systems and I’m now thinking about going back to school to follow my childhood dream of developing video games. I plan to get two associates degrees in Mathematics and Computer Science at my local Community College and then transfer to 4-year University for either a bachelors or masters program in Computer Science. Most universities in Southern California don’t offer a second bachelors program for Computer Science so I’m probably going to have to take the Masters Program route. However, because I’m coming from a different field of study, I’ll have to take some remedial upper division courses for the program. I’m confused though as to how I can take these courses as upper-division courses aren’t offered at Community College. So my only option would be to take them while in the actual Masters Program but it’s stated that I cannot get a grade lower than a B+ which sounds pretty intense. Is there another way I can take these courses without the B+ grade requirement?
https://www1.cs.ucr.edu/admissions/graduate.2

Go visit the grad program that you are interested in. Bring your academic records with you. Sit down with the grad advisor for that program, and go through your coursework to find out what you need to pick up before applying, and what you would be able to take after getting admitted. They will tell you. This is not a wheel that you need to invent on your own.

you can take upper division classes as a non-degree student. For example, most/all UC campuses offer an Extension program. Arizona State offers online classes which might work as well.

https://elearn.extension.ucr.edu

@happymomof1 Thank you for the feedback, I’ll be sure to do this once I get my lower-division classes at community college out of the way.

@bluebayou Thank you for the tip, but I checked their website and it looks like they only offer some lower division courses at the extension center. https://www.extension.ucr.edu/course_schedule/19303857/educationandcredentials/subjectmatterspecialization/computerscienceeducation