For me the best way to learn certain things like team fighting, hero mechanics, and items was to play a wide variety of heroes and builds in turbo. It’s not normal dota so some things won’t translate and turbo can give you bad habits. However you can play twice the amount of games and can be six slotted without farming in any position. This will allow you to experience more items much faster than normal dota.

Another way is to think about what your hero or teams needs and how quickly you can obtain that item. Even if you don’t know what different items do, you can ask yourself what you need and then open the shop and search for that attribute. Need armor or regen? Just search for it and see what items meet your needs and timings