Hi. I wanted to know how the army support soldiers with children under 15? Are there schools available for them?

Hi, there are many service personnel who have children either whilst serving or have children and then choose to join up. The Army has a Army Parents Network which is great for every day questions or issues and often issues can be solved through this network. Many camps have nurseries either on camp or nearby. Children of Service personnel would usually go to the local primary or secondary school. Schools who take on 'service children' are given extra money from the Govn to provide additional support (it also encourages schools to take service children). The MOD provide a system called Continuity of Education Allowance (CEA) for service personnel to put their children (from aged 8) into boarding school - to provide a continuity of education when the service person moves around. The individual still has to pay a minimum of 10% of the boarding school fees.
I have 3 children. I had my first less than i year after I joined and I was on a camp which had a nursery (in Germany). When i moved back to the UK my children went to a local nursery (5mins from the house) and all of them went to the local Primary school (along with many of the military kids who lived nearby). When my eldest and middle one got to secondary school age, i chose to put them into boarding school. My youngest will have done 3 primary schools by the time she hits secondary so i am looking at boarding school options for her next year. Many families choose to keep their kids bouncing around different primary schools but choose to put them in for stability at secondary school.
Regarding your flat - it's up to you! You could sell it, or rent it out or if you end up based near to it after Basic Training then you could live it in? I hope this helps for now.