My best advice to a new all grain brewer is to relax. Then read How to Brew by John Palmer.
It’s really not that hard. One of the most interesting things to me about brewing is that every step of the brewing process can (and does) happen naturally without human interference. As a brewer, we’re really facilitating reactions and manipulating a natural product to create the product we want. All of the enzymes, nutrients, and naturally occurring preservatives are all present in the ingredients that are required for making high quality beer. Barley’s husk and ability to crush the barley without destroying the husk material is even the perfect filtration aid for a mash/lauter. All a brewer has to do is facilitate the necessary enzymatic reactions to start brewing a beer — you can do it.
My second best advice is to follow a simple routine and recipe. Something like a Pale Ale (Pale Malt + C60, Cascade, US-05) via boil in a bag, No Sparge, or batch sparge before you attempt the Double Peanut Butter Imperial Smoked Lager via Triple Decoction.
Other than that have fun and take notes so you can make adjustments in the future. You’re gonna make beer but everything probably isn’t going to go as planned.