Nothing to be nervous about. All kinds of idiots and lazy people get hired by retail parts stores. Having automotive knowledge is a plus and will help you move up. Showing initiative, keeping things clean, being punctual, etc. will all help a lot too. A lot of people just show up to collect a check and it's not too hard to do better than them. If your manager has half a brain or gives half a [censored], they will notice.
The day to day tasks in a retail store are pretty basic and there are procedures for everything. Once you learn the ropes, most things are a piece of cake.
The hardest part about working in a retail parts store is dealing with the general public. A lot of people are clueless about cars, but when their car breaks, they are desperate to fix it as cheaply as possible. They want the magic "compruter machine ya'll hook up to my cah" to diagnose everything for them, and if it can't they want you to diagnose it for them, show them exactly how to fix it, and maybe fix it for them. Corporate policy generally mandates that you treat them like people and hold their hand as much as possible because "every customer matters," but it can get frustrating quick. The tool returns with walk ins will drive you nuts too.
Hopefully the store you work for will have a boatload of commercial accounts. Stores with lots of commercial accounts are by far the best to work for. Ones that rely mostly on walk in idiot traffic, not so much.
Things you may encounter...
- "Ay, come look at mah cah, why dis A/C be blowin' out when I hook dis hose up?" (customer holding A/C recharge hose with valve wide open and no can attached)
- "I think my Gran Marqueesee need a fruse or some [censored], I don't know why dis [censored] ain't workin', ya'll got that compruter machine?"
- "I need a Chebrolet carbratea gakket...it be a sebenty one, or a eighty fo', I don't know..."
- "The mechanic say I need a suspension joint...how much dat cost?"