OP, you're still learning having just passed your test, without an instructor to help guide you, so you're bound to make some decisions that more experienced drivers wouldn't and also make some mistakes (everyone does). You'll also encounter a small number of other drivers that are idiots. Try not to let one driver knock your confidence. Well done for getting out and about in your new car on a quiet Sunday morning, keep practising. You might also find with an MMT gearbox, that you don't need to reduce your accelerator pressure (and therefore speed) when a gear change is imminent, just don't push harder to compensate for the slight drop in power, to keep the change smooth. I'd also say that if you're driving a 1l engine, you're going to get overtaken a lot, by frustrated drivers, because you don't have any power going up hill (I drive a 1l and it's a total pain and I wouldn't recommend it at all for a new driver).
However, you don't need to worry about getting flashed on a speed camera doing the speed limit, so there's no need to slow just for a camera. You say yourself you were doing 27 in a 30 zone and slowed for the camera. No need whatsoever. If you need to slow for the conditions, then fine, but if you're travelling at or slightly below the speed limit, see a camera, then you just carry on as you are. People who slow below the limit for a camera, when they were driving at the limit before, are annoying.
Although it is possible to have a fixed penalty for just 1mph over the speed limit, this is unlikely as the Police need to take into account the tolerances of the equipment they are using. There are usually a few mph of tolerance before triggering a photo or fixed penalty. Plus it would be hugely impractical to fine everyone doing 1mph over the speed limit going through a camera. They will want to focus (limited) resources on those going significantly above the limit.