Hello Cody. I went to Southport flower show at your age and was amazed at the big onions on the Robinsons stand.
I grew Kelsae onions this last year. I started them in a greenhouse in February, and planted out in May. The biggest was 2 ib 12oz which is a tiddler compared to some that are grown for size. For huge ones, they are sown before christmas, in heat, potted onto individual pots, use growlights to extend the day, and grown on in greenhouses in big buckets of soil.
For very long carrots,(and parsnips) they construct boxes filled with sieved sand, use a crowbar to make a hole, fill the hole with sieved compost and plant a seed in the top. they are also grown in big polytunnels.
Medwyn Williams in anglesey holds the records for a number of veg. his website is
It is fairly easy to get big onions with Kelsae, provided you plant in rich soil and they get plenty of sunlight. Good luck.