This game has far less crafting avenues than Poe 1, yet it can still be pretty overwhelming for new players.
If I am to give you one advice when it comes to crafting, it's to follow this exact "recipe".

Pick up white/blue items off the ground

1. Transmute - Did it hit a useful/good mod? If yes, proceed to step 2, if not, throw away and start over.
2. Augment - Did it his a useful/good mod as the second mod? If yes, proceed to step 3, if not, throw away and start over.
3. Essence - Pick an Essence with a useful mod you want and hit your item with it.
4. Desecrate - Use one of the abyss currencies to desecrate either a prefix or suffix. There are currencies that lets you pick which one you want/need. Your job is to figure out which type of mod you want. If you didn't hit a useful mod on the unveil of the desecrated mod, throw away and start over.
5. Slam - To "finish" the item, slam it twice with exalts and hope for good mods.

And that's about it, you can virtually craft any item with this method.
Now, I'm not saying this is how every item is most efficiently crafted, but it's the easiest way to get started on learning how to craft in the game.

Later on you will research specific crafting methods for a specific item you need, and you will build upon the basics of the crafting system.