As far as your credit profile goes it depends what is on their, lenders will generally go back the full 6 years but might ignore things over 3 years old and satisfied or minor blips of a more recent nature. As a general rule they use Experian or Equifax (to a lesser extent) so obtaining a report from one of these is a good starting point.
Do you have any missed payments, defaults or CCJs? If so there are still lenders out there for you but you would expect the rate and deposit required to be less attractive than your high street lenders. The actual score isnât always a massive indicator of how good or bad things are as the lenders have there own internal scoring systems anyway and some will credit check rather than score so there is not a mysterious number you need to hit. It helps if you are on the voters roll.
If you are looking at a shared equity or ownership arrangement you may find that the part you are not effectively buying will count toward the deposit and this makes the application more attractive as the mortgage company is only in for 75% of the value and has first charge should they need to repossess, other help to buy schemes at 95% have guarantee schemes backing them provided by government which also helps. If you are buying with a partner who has a pretty good credit profile that will go a long way as well.
And yes, the adult world is insufferable generally because of all the pricks and wankers.