I would love to settle in the Uk , but how to do it legally ?

Hello there , i am romanian , i am 21 and i work as an au-pair in the Uk.I have been here for the last 10 months and i am planning to continue staying more with this occupation. Long story short , i came here after a quick Skype chat with the family and i am here without a working contract. I want to know after i am "done" with the au-pair stuff and i'll have a nice amount of � in my account , what do i need to do / get ( in terms of paperwork mostly ) to settle down with my fionce (au-pair and romanian too , same age ) so we can get our rent and jobs , to live like a nice couple in a beautiful country? I do own a full UK Driving License and a Barclays Debit Card and i am insured on a car, so thats all i basically have , along with my Romanian Id / Birth Certificate and a Interior Designer Certificate. I really could use some advice. Thank you very much for reading