jamie first off what budget are you looking at?
i understand that you are only twelve so obviously price could be a problem.shakespeare do the zeta pole which is 11 metres long.it comes with a spare top 3.priced around ?90.if you have a bit more money mavers poles are spot on.i have three of them.
as for advice you should have a good idea of presentation with you having a whip,just shorten the line from pole tip to float so that you have a short amount of line,so,when you get bites by striking quickly with a shorter line you'll hit more fish.
as for elastic and mainlines and rigs this would be easier to advise if i knew what sort of fish you are after.
buy yourself a couple of clip on pole cups to ensure feed goes on top of your swim and not haphazardly as when you throw or catapult bait out.
have a look at a pole roller for when you play the pole backwards when landing fish.
if possible make up your own rigs rather than buying ready made,it's more fun and more economical in the long run,plus if you buy a rig that's ready made and you lose a fish on it it's someone elses fault not yours.if you make a rig and the hooklink snaps you swear and tie on another.
have you got a seatbox?polefishing is easiest on a box,you have to sit upright for quite a while whilst pole fishing.if you can get in your local tackle shop and tell the owner how much you've got and what you require.most tackle shop owners will throw a good bit of kit together and are only glad to help.before you buy a pole though,ask to sit on a box with your chosen pole at full length and see how it feels,don't buy a pole or any other item of tackle that you feel uncomfortable with.if it don't feel right leave it.don't think that you have to buy it.when you find one that is really comfortable ask how many top kits come with the pole.my first pole was the shakespeare bungee extreme that came with 3 spare top kits.the more spares that you get with a pole is another good indicator of a quality pole.sorry i can't be of more help at this point,if you email me direct about what venues you will be fishing,i will give you a few pointers on what rigs to use.good luck.