1. Have you ever seen him fight?
2. Do you know his favourite tecniques (or tricks)? Most self taught - instinctive fighters will have a minimal set of tecniques that they like and work for them, and use these at all times.
3. Is it going to be a stand-up punch for punch/kick for kick fight with boxing gloves and such? Is there a chance that he will grab you and try to wrestle you (being as you say alot stronger than you, that would be to his advantage, as in a wrestling contest, speed and tecnique will not matter as much as pure strength and endurance, unless you are a *really* good wrestler)
4. Do you have some kind of plan? What kind of fight do you think would favor you based on how you assess your skills? There is much to be said about responding to the other man's offense, but it's a good thing to try to force on him your own strategy. (move the fight away from things you're uncomfortable with - think of ways to sabotage him)
As you said that he's your friend I'm assuming you don't want to cripple him, or use excessive force (adrenaline can make you do this even without meaning to). Can you expect a similar courtesy on his behalf? Is it a friendly fight, or a "friendly" fight? (Is he pridefull?)
Honestly, I think that a year of training for a previously untrained person is not too much especially to help you keep a cool head under pressure (but could be enough). Have you been hit or wrestled in the gym? Do you know how you respond to blows?
If you don't give us more info on the rules of this fight and your "opponent" I really don't think we can contribute much.
To sum it up. In my opinion:
Get in a "serious" mental attitude, at least when the fight starts.
Compose yourself, guard yourself well (be wary of unorthodox attacks).
Be mobile and try to "work" him. No short bursts of energy. Frustrate him, work your distances start your attacks from as far as you can make them effective (really connect) and follow through relentlessly (don't stop after you "score" a point, keep going until you can disengage on YOUR terms)
Finally, try your best to win but ...
use your adrenaline don't let it use you!
Try even more to "give him a good fight" and make him sweat for the outcome.
Some people will probably disagree with the above and tell you to go all-out and confident (but there is only so much positive thinking will do, if not backed up by actual skill!)
Most importantly since you're a relative newbie
do you like what you're doing, have you "found your path", looking back over this period do you see yourself improving, do you expect that in regardless of how good you will be at the end of this year you will be twice as good by the end of the next?
If you answered yes to any of these I think you'll do OK (in this fight as well as others)
Take care (but push yourself
)