its fine to get a mortgage on one salary, basically each lender lends on a multiple of your household income, some 2.5 up to 5 times salary
So if youre earning £20k 2.5 would lend you £45k, 5 times would be £100k, they'll take into account your outgoings and if you'll be able to afford it.
Rates vary from lender to lender most lenders have a mortgage calculator on their websites so you can work out how much it will cost per month, dont forget that you'll need buildings and contents insurance and probably life assurance too.
Getting a mortgage is quite easy now, you can do it over the phone or online, the part that takes the time is finding your property, having the survey, exchanging etc.
Some lenders offer a mortgage holiday at the start, which might help you out a bit financially at the start.
Best thing you can do is speak to a financial advisor, make sure they're independant i.e. not linked to a bank, most will offer this service for free as they eventually get paid commission from the banks. they should be able to take your income, outgoings and how much you want to borrow into account and will let you know what your chances are.
Good luck!