Decide first if you want your apple trees to be
Standard
That means a big tree you will need a ladder to collect the fruit from and you need to have have loads of space for it
Cordon
That means it will climb along a wall or a substantial fence
Miniature
That means they will grow in a big tub or wont grow too tall.
Ballerina
They grow on a single branch and do not spread like normal trees.
Next think of the type of apple you like. Is it for cooking eating (for taste) or keeping for both cooking and keeping.
The size of the area you have available can dictate the type and variety of apple tree suitable for you.
Forget the apples available in shops. (often imported) You can, with your own tree enjoy apples that are not grown commercially and there are loads of them with wonderful flavours.
I will say one thing at this point. Watch out for being tempted to buy an apple tree which has beautiful red apples. As yet. I have not found a red apple brilliant to eat, nor have I found any one who has tasted a beautiful looking red apple who will tell me that they are scrumptious.
An apple tree is for life. So make sure that you get a variety you will enjoy especially if you only have the space to grow one variety.
If need be wait a year to decide after tasting a few.
Three Examples are:-
Coxes Orange Pippin Lovely taste and they keep fairly well
Russets, outstanding flavour but they do not keep well
Bramley
Are a superb cooking apple, very sour but most British people adore them cooked with loads of sugar. They need five other varieties of apples nearby to pollenate them properly BUT that could be within two miles so don't be put off if you want cooking apples.
An apple tree sounds like a wonderful idea but my personal advice is:- WAIT until you have tasted a locally grown apple you love then buy the tree. Taste is personal and with so many varieties available, why go by what other people tell you or look at a pretty picture in a catalogue?
I have all the above and a Worcester too. If I had to chose I would keep the Bramley then the Russet. My dear departed father would have kept the Coxes Orange Pippin My husband would prefer to Russet. to all the others Yet my daughter thinks the Worcester is the best.
My grand daughter likes Golden Delicious best and buys hers rather than eat what we grow for free.
Ard Werk Innit?