You can pretty much use any starting book for beginners that you can find, afterwards I always find the Matlab's own online help very useful and handy:
Many publishers are allowing students free downloads of certain books during this pandemic. I have seen several Matlab books on the list. The books are below.
Can you tell us what types of problems you interested in solving with Matlab/Simulink? The reason I ask is that it is always easier to learn software when you have a specific problem or goal in mind rather than simply trying to learn everything about the software all at once. There is a bewildering amount of 'stuff' in Matlab/Simulink, and most of it you will probably never use.