It is true that the quality of the spore prints you have taken is primordial for further experiments from these. Starting petridishes at the beginning isn't a good idea, in my opinion, because it requires already some more skills and equipment.
Liquid culture is a good start, especially with prints that are not completly made in the state of the art.
I handled to get fruitings from wild South American Cubensis Prints that were harvested totally unsterile and "like not to do" with liquid culture. It requires little equpiments and doesn't take a lot of time.
Beginning mycology is surely not easy but like the others said: method and technique will help to go further little by litte.
I like the book by Peter McCoy "
Radical mycology".
Inside there is a whole chapter about how to get into mycology which is quite inspiring with a lot of little tasks and manipulations to get familiar with the processes.
I recommend it highly for beginners in mycology!
Arthur Dee was one of the greatest alchemists of all time, not likely to his dad, I forgot his name, this small James Bond sorcerer working for the queen of a... Hail Arthur!