I think it is always hard for someone first starting with tarot, to understand the process and how they can use it. The Thoth deck is a certain type of challenge also as it comes with a great deal of occult attachments, though these aren't necessary to use it for readings.
When I was starting with the Thoth I found
this a really helpful book. It has a range of meanings, and advice that is more specific to someone who wants to use the Thoth for reading primarily.
If you wanted to get more into the occult background, then I'd suggest
this as a good place to get started.
I'd really suggest also working with one card readings. Actually with the Thoth the more I know, the more I prefer a simple one card reading as there is so much information in it. But when first starting I found it good also to have a specific question, pull a card, and spend some time thinking about that specific card in the context of my question.
Welcome to the Thoth forum!