When you begin to study mycology, you quickly realize that you need a microscope to work through the keys, which will ask you to check for you to check for things like the shape of the spores. For Christmas, I bought myself a couple of cheap used microscopes from eBay---a dissecting or stereo microscope, useful for examining large things like beetles, seeds, and lichens, and a compound microscope for examining fungal spores.
I got the stereo microscope in yesterday and have used it to look at beetles and lichens. Those lichen keys are easy to work through once you've got the right equipment. I don't know when the other one will come in. It's currently sitting in a post office in Mumbai, according to the tracker.
To examine fungal spores, not any microscope will work. You need one with a x1000 oil immersion lens. This page explains how to use it to look at mushroom spores: https://www.mushroomexpert.com/microscope.html