I had my first game handed to me by a more senior player, as he was using a brand new ork list he was itching to try out. I asked him to be honest, and he admitted that he did not want to nail me to the ground on my first attempt. However, he did give it a shot and it was a close run thing. Over the first six months I think my score sheet was W3 D1 L9
I was pretty demotivated as I lost 9 games in a row. I spoke to some fellow beginners and they felt the same way, but encouraged each other. A lovely bit of advice was that for the first year plan to lose 60-70% of your games. mine came up to just under 70%.
I guess the general consensus is to evaluate each loss as it comes, try and recon each force, and a bit of guesswork on possible force organisation helps a mile. Ask for help if truly stuck, and discuss with your opposite number how they viewed your force and how they might have arranged the forces on the ground better, reserves, different troop choices, etc.
As a previous Secondary school teacher you learn not to let a bad lesson get you down. Just learn from your mistakes and don't be defensive when someone gives you constructive criticism. I like a quote by Corvus Corax in Deliverance Lost which emphasises the mentality people need when starting up- 'Attack, retreat, attack again'