What to do when I want to move out of ex boyfriends house with our baby in the uk?

We have been together 3 year lived together for 2, we have got a 4 month old son together and we have decided that the arguements is not good around the baby so we have split up our lease runs out of our rented house the end of this month so how do I go about moving out, the baby will be coming with me as I am the main caregiver but as I am on maternity leave I only get �128 a week so really can't afford much. can any one give me some advice on how to go about this and what to do next please? I don't need relationship advice tho because we have already decided x