How can I get some credit history when no one will lend to me?

[Babysealion]

I'm expecting a baby in January and me and DP are saving up for a mortgage. We both work full time.
I'm 18, DP is 22. Our combined income before tax is around 28k a year. However I'm worried that I won't be able to get a mortgage and I have absolutely no credit history. No one will lend to me.
In May I applied for a New Look store card - rejected.
August applied for a Barclaycard - rejected.
Just got a rejection letter today for an Aqua credit card which is apparently specifically designed to help those with no credit history or bad credit ratings to rebuild credit rating.
My phone contract is paid for by my grandad and DP has a car on finance, we private rent. DP has a credit card which he is paying off.
I'm not looking to spend money I haven't got and build up debt - the plan was to put some purchases on that I could afford without the credit card, and then pay it off when the bill comes, just to build up a bit of credit history! Argh. Any advice?

If you are going to go to university, do you really want to decide now where to live? You may well want to live near university.

Pay off debts. Avoid getting into debt. Build up a savings pot, as the larger the deposit the more choices you get of lenders when it comes to getting a mortgage.

Get a catalogue.

"With renting, I just feel like we have no security and it feels like money being poured down the drain IYSWIM - we're going to pay a lot in rent overall, with nothing to show at the end of it, whereas when you're paying off your mortgage, the house is actually yours, which is why we're desperate to get onto the property ladder as quickly as possible."

Owning a house a good long term ambition. But getting a mortgage aged 18 when your combined incomes are low, you have a baby and are hoping to go to uni isn't sensible!

There are lots of advantages to renting - you don't have to pay the house insurance or get a new boiler if it dies. It's cheaper to move if you two end up getting jobs somewhere else. If DH loses job or has hours reduced, it's easier to get help with the rent through Housing Benefit than it is with a mortgage.

When you are a student you can get your student account with credit card! Really not a good idea to get a mortgage based on 2 salaries when very soon you will be down to one! After your degree when you're in a graduate job ( hopefully) you will be plenty young enough to start with buying a house.