You have 5 years experience; what did they charge at your last shop? Start there.

I’d figure out what your overhead costs are. For example, my insurance adds ~5% to the cost of everything I do.

You can figure out some of based on what local dealers charge for parts.

Do you work on foreign or domestic?
Average cars or higher end stuff?
Do you have all the scan tools and online tools?

I’d look at some of the better you-tubers who do work and figure out their rates.

If I were you I’d try to find a local mentor. Those are things that should have been known before opening. Usually can find one via local business associations/groups. Best wishes, but just make sure you make enough to pay yourself and employees fairly, plus cover expenses, plus cushion.

Pricing should be competitive.

Assume local Chevy dealer is charging $140 and pays employees $40 or $50 whereas Porsche dealer is charging $300 and pays employees $75.

You need to find sweet spot for the market.

You need to charge a lot more than what mechanics make but less than dealership rate so you can capture the market segment(s) you are trying to target.

As for price, your value proposition to customers as mechanic is the ability to deliver services whereas parts can be necessity.

So, instead of marking up the price of oil, charge a disposal fee instead (i.e. $15). Same for brake parts, muffler, CAT, etc. You have dumpster to fill up but not all of your waste can go in there.

As for how to quote, I would secret shop to determine how the local competition is quoting such as Jiffy Lube, Meineke, and local car dealership service departments.

I would mirror what they are doing so consumers can compare apples to apples.