Bit late but a couple things I always hear being said to beginners;
-try not to use brute force. Will be difficult without knowing many techniques, just bear this in mind.
-tap. Forget pride, forget seeing how long you can resist, when you're caught learn when to tap. You'll learn quicker and will less likely get injured.
-escapes and improving position is way more important than learning submissions at this stage.
-focus on simple techniques/drills involving hip movement (e.g. upa, shrimping - google/youtube these).
-keep practicing the drills in class rather than stopping to talk or sit and watch others.
-pace yourself. even if you're fit your body probably won't be used to the kind of movement involved so take it easy and relax :)
RELAX would be my only advice and keep training, Ive trained in the gi consistently for 2 and half years now after training on and off no gi and MMA since 2005 I honest believe it is the greatest thing I have ever done, I have never been so engrossed in training as I have been during this past year.
Give the Carlson Gracie school a go!! (I say that as I train at Carlson myself although Kent based).
It's going to be tough - Probably the toughest thing you'll have to endevour for months on end. I'm at 3 months and it's brutally tough. You'll get subbed by allsorts but the most important thing is to grind it out and stick with it.
I have been assured that it does become a lot more fun once you nail the fundamentals.
I gotta say that despite being subbed everytime I roll I do still have fun and hold out for the day finally I sub someone myself with a proper move!
Go to each of the clubs (both are very good) and try them out, just explain to the instructor your position and you are looking for a school that is right for you. Be very open minded and the biggest thing is to enjoy it. BJJ is so addictive and hopefully will become a huge part of your life.
cheers for the info peeps