This a question about how he knows how to use each of them and one in particular, the Time Stone.
I say the Time Stone, because this is the only Stone we are really given any information on how hard a Stone it is to use. So it is not just "pick it up and you can bend time". You actually have to train and study to use it and I am guessing if it is not close by, trial and error (as with most training won't cut it).
In Doctor Strange we see a conversation with Mordo on how hard it is to actually use the Time Stone.
The only hint we get that Thanos may already have the knowledge is in this scene:
Stark, you're not the only one cursed with knowledge
So, we know Thanos may have a great knowledge base, but is there anything on how he knows how to use the Infinity Stones?
Is there an in- or out-of-universe explanation on how Thanos was able to use the Stones he only just acquired, considering how hard they were to control?