RF design is a very broad and specialised field. It is not uncommon to find books covering just one subject, antenna design, impedance matching, or filters come to mind.
If you are new to the topic, I suggest that you look to ARRL and RSGB sources for an overview of the subject, although they are amateur radio oriented, they cover the topic in some detail, however they are not text books.
Do you have a good grounding in maths, there is little escaping it if you are to take the subject on in any depth. It would help if you could say a little more about what your interest is, to narrow down what to suggest.
There is some interesting info here,
https://www.reddit.com/r/rfelectronics/comments/i4tbu2/an_rf_book_list/,
but obviously this oriented towards university study, so most of it will assume a minimum back ground in electronics and maths.
There are free online resources that may help, as well as a few book preferences in the following links, ,
http://explorerf.com/conquer-radio-frequency.html,
https://www.rfmentor.com/,
https://open.umn.edu/opentextbooks/textbooks/753,
https://forum.allaboutcircuits.com/threads/rf-circuit-design-books.67394/See if any of the above helps, good luck,
cheers,
Richard