Having a good understanding of radio repair is a very good start to understanding TV.
It be a good idea to download a book or two about TV repair.
It seems that many people are not aware of the huge amount of knowledge available online. Ask and download and you can get a library that would have cost thousands of dollars.
Look for "How to Troubleshoot a TV Receiver" by J. Richard Johnson, about half way down the page, blue cover. This edition was published in 1953 so it will not contain info about transistor circuits but the basic function of a B/W TV is the same. Some test equipment is different also.
https://worldradiohistory.com/BOOKSH...helf_RIder.htm
Finding info about solid state radio and TV circuits is a bit harder to find. In later years basic practical solid state troubleshooting was published in magazines. Magazines are available also but the info is spread out among them.