If I’m not supposed to send a transcript to the UC and CSU schools, how are they supposed to know my grades? Am I going to just type
them in somewhere on the application?
Yes, you self-report courses and grades on the UC and CSU applications.
If you are admitted and decide to attend, you send your final transcripts to the school you attend, which will then verify your self-reported courses and grades (also, the school will want to see that you did well enough in courses that were in-progress at the time of application).
Yes, so be careful when you self report on the application. Don’t make mistakes, check everything over carefully.