Having only been AG brewing for 16months, I can remember first hand the sleepless nights leading up to my first AG attempt. Then you mash in and realise that all the horrors you have read about in the text books are real worst case scenario's and that it's actually a pretty straight forward enjoyable process.
You'll make a few simple errors (mine was too hot a mash), but when you taste the first drop of your first AG it will be marvelous and you'll never look back.
Your main issue then will be knowing when to stop!!
If your ingredients are pretty fresh, your temperatures pretty close to ideal, your timing right and brewing equipment properly sanitised, there should be no issues. The golden rules i have adopted are.
Make sure everything is to hand before you start.
If you're drinking as you're brewing, set an alarm clock for each of your timing intervals as you will forget.
And a useful one for the first few brews is to write a ticklist of all additions for the boil with times, weights etc. That way you don't forget to put something in (I kept forgetting the irish moss or protofloc)
There are a lot of old wives tales about brewing, which make people more wary of it than perhaps they should be. It's a fun way to spend half a day!!!