Apple tree pruning and other problem please help

kristine015

Hi I have 3 fruit trees,

- Cox‘s Orrange Pippin Malus

- Laxton Fortune Malus

- Conference pear.











I live in the UK Northern Ireland.

I have had them since 2013 and was always in a large pot. The two apple trees has had some flowering and fruit for the last couple of years but very little fruit I am talking about 20 apple max.
I am guessing its due to poor soil care and lack of cuttings and being on the pot. Last  autum start of November 2017 we decided to move all the trees on the ground and fed them some bone ash. Again I fed them bone ash just last week for the spring 2018. 

My problems

1st- Pear tree always produced flowers but never bear any fruit. I am hoping this year it will since we transfer from pot to ground and ground fertilized last autumn and just las week. - can anyone please suggest what I may be doing wrong or what it lacking?  

2nd - I’ve never done any cuttings/pruned any of my tree. I have done some online reseach of how and when to just recently. I always thought it was better to leave them the way they are and never really done any research before now.
 I do think I can manage the Cox’s Orrange Pippin tree as it is just straight upward position. However my second apple tree - Fortune Laxton Malus - it has 4 leader head. I don‘t know which is the main leader head as they are all the same size and almost sprouted equally I am afriad I will cut the wrong one and or I am wondering should I even prune it or just let it be? please help. What do I need to do?