Welcome to the forum
Just stick to 100% coco fiber.
As for tips you'll learn quickly as you go along so I'll just give you a couple to begin with:
1) To raise humidity, pour (don't spray as it is ineffective and has to be done daily) some water onto the coir so that it is damp but not soaking or bog-like. You want most of it to go a darker shade when you pour the water.
That should give you about 80%-90% and last for a week or two before you repeat the process.
The other benefit of pouring water onto the substrate as opposed to spraying is that it enables strong, solid burrows.
2) Everyone ends up asking this at some point
Don't worry if he doesn't eat - they can go a year without food.
They will also often fast for long periods of time - this could be due to the fact that they have previously gorged themselves, they are preparing for a moult or birth or for no apparent reason {they do this sometimes}.
Any questions you may have, feel free to ask.
