I’m down south, so have never raced in Manchester. Try looking on the net for a local Triathlon club, there are a lot about. Give them a bell, it’s good for training, technique tips, local races, sorting out open water and you get 10% off at some tri shops.
I’m sure you will find a local lake again try the net. Don’t use a surfing wetsuit, they are slow and give very very bad blisters if you race in them.
For a first even maybe look at sprint, otherwise go for the full olympic distance. Its not to hard and you will be fit from biking, I know a lot of people that did it as their first event.
For the bike look at getting some Tri bars, if you learn to use them they will take a lot of time off the cycling but I know a lot of people hate them.
Hope that helps.