Auto-entrepreneur for garden machinery business?

I am considering setting up a garden machinery business e.g. small tractors, ride on mowers, chipper/shreadders, log splitters, rotovators etc. My plan is to buy and sell used machines, offer servicing for clients own equipment, supply spare parts, hire machines to clients etc.I live in a rural area in 81, have a large barn/workshop at my property, and I have the mechanical skills and business experience from my previous life. I have been researching the market since the beginning of this year, and believe there is demand from both expats and locals. The main competition is the generally overpriced main agents for the machines.

My main revenue will be from sales of used equipment, where the gross margins are likely to be in the 20-50% region. Spare parts whould have a higher margin, but will account for less than 10% of revenue, service will account for around 20% and hiring out of equipment for about 20%. I am looking to turnover around 20K in the first year with perhaps a gross overall margin of 12-15K. I will then have expenses on top of that. I know it is not much, but I would like hit my goals and then grow next year. Do you think auto-entrepreneur is the best set up for me? Is there anything I should be aware of before making my application? I want to make sure that I get it right first time if possible. What about insurance ?