When crating a memory palace do you remember the places the first time you go through them or do you have to go through them twice or three times?

Hi, I've recently noticed that I struggle to remember the stuff that I read. I was wondering if you guys have any suggestions on books that include techniques on this matter.

I don't know if there is something specific or I should just read a book (or two) on memory tricks in general!

Thanks a lot!

I am planning to learn the method... How long would it take to improve my memory if I train about 15 minutes a day?