Prestwick has a lot going for it if you live in Kilwinning rather than Central Scotland. Prestwick, (ATC & School) have been very friendly when I've been there, on my Nav Test, my QXC and when I had to Wx Divert there when Oban got cut off by rain.
A friend of mine is doing his circuit training at Perth as there are no landing fees, so that saves quite a bit of money compared to Cumbernauld or Prestwick. Once he has done his solo he'll go back to Cumbernauld for more lessons, but expects to split his training hours between both airfields as it will give him more experience.
The big advantage, at a price, of training at Prestwick, or any full ATC airport is that you can go to another one without being nervous. I know some people avoid "Edinburgh West" BECAUSE they have ATC rather than using that as a reason to talk to them. Another advantage is the length of the main, big looooong downwind legs, loads of time for checks and height adjustments.
The downside is that at Cumbernauld or Perth, you can almost always, startup and go, and when you rejoin and land, you park right away. Holding at Prestwick can be expensive and makes the paying for the landing fees seem all the more unfair.
There will be days when you arrive and don't fly, but as a student, very few of those trips will be wasted. Sit in the aircraft and run through drills, or just concentrate on looking at the view from the driving seat when on the ground. It helps you know where you are when landing. Practice operating the Trim. Flaps, Carb Heat, Radio and Transponder (with power off) and you will find it easier to do when you are in the air. Doing this stuff is free, and it should reduce the time that you need to pay for.
Ask instructors (and students) if you can sit in on their briefs and debriefs, there will be learning points for you in the work that others do , whether they get it right or wrong.
Listen to ATC on a scanner (don't buy one without a full numeric keypad) and become familiar with the chatter so that you can pick it up easier in the aircraft.
There is an emotional cycle of change during your training, and at times you will find yourself on top of the world and at other times you will be in the well of despair. No matter how you feel after a lesson, bear in mind that the phrase, "This too will pass" is very relevant.
If you want to do it cheaply, do it often, flying is a perishable skill, especially when you are a novice.
I took a video camera with me and recorded my instructor doing a "perfect" circuit. I watched it for hours that night and went solo on my next day at the airfield.
My final tip for today is this: Write up your logbook when you get into the clubhouse. Don't leave it for when you get home. But, get a diary, (a big A4 page a day jobby) and when you do get home, write after each day's flying, what you did, and more importantly, how you feel about it.