Every airline has different requirements regarding cabin crew. To be honest, I all goes down to your attitude and ability to work with others as well as passengers. Some have higher age limits than others.
You need to work out what is important to you. Where do you want to be based? Will you be willing to move? Can you afford it - basic salaries can be very low and you won't start earning full allowances for, realistically, the first couple of pays.
As you live in Liverpool, you are probably best to give Easyjet a try. Get a solid grounding as crew, then move on to other airlines if you want to do long haul. Other than that, I'm sure you could try one of the charter airlines based at MAN.
Best advice is to do your own research. Look at every airline's website. See what their requirements are and work towards them.
Good luck.