How should I ask them? Should I just go there and ask or what? I feel like they’ll look at me as a kid and look at me weird.
I want to commend you for asking for help, if you are able to do this at a younger age and continue to do so as you are older, you will be wiser than most people. This a great idea you have to work at the lfs.
First things first, when you walk into the store either ask for the manager or owner if available. (If you don’t already know who that is). You always want to talk to whomever is in charge because they will have the final say if it is a go or not. Give them a firm hand shake and look them in the eye, when you introduce yourself. Let them know your situation that you are looking to finance your fish hobby, and offer your services. Let them know that you are willing to do, whatever they can train you to do. Be a sponge and soak up any training they give you. This will be impressive to them.
Don’t say you will work for free, you can get yourself in a hard situation if you do that. But let them know what you are looking for- example: I am looking to make a small wage in order to buy more fish/ supplies and possibly more tanks. Typically if you work for them they will give you a deal on those items anyway. Asking for a small wage tells them that you know what you are after and it lets them know you have some maturity on you rather than being an indescisive child as you do not want to be seen as.
Then do your best to follow the leader. If they ask something of you, do it. If you don’t know how, ask them to show you how to do it so you can do it on your own next time. When you learn more skills, that creates value for the owner, manager. Always look to create value and you will find favour. Be their favourite and they will promote you, and that typically means more responsibility, more responsibility =more money.
While you are doing this, also negotiate a better allowance from your parents. Do chores and whatnot so they are more willing to give you a better allowance. Assuming you already get one, if not might as well try to get one. Try both at the same time and you will have a steady income in no time.
I did these things I told you when I was your age and I always seemed to have the stuff I wanted for my fish, bikes, a scooter when I turned 14 and had a learner liscence. I lived in a small town so a scooter was awesome to drive to the pet store I worked at. Now I own a business and employ roughly 10 people and some of which are very young and doing what we are describing here.
Good luck Sir.