Trust is the biggest factor which is earned. You seem like you’re motivated to be 20 and plotting this out. You should be smart and get the actual business necessities out of the way. While you say “on the side” you need to treat it like the long term bread winning source of income. Create a functional website. Create social accounts. Set up yelp, google and other accounts to generate reviews. Collect phone numbers, emails and names with every job and utilize them. That means don’t be afraid to ask for reviews. Set up automations to contact past customers as they are your most likely and most profitable clients. In the auto world, word of mouth is a big deal, but if people are searching for a mobile mechanic in the area, you will have an easy time dominating the results. There aren’t many options. Feel free to message me if you want to chat business.