I'll pass on talking about the trucking, the otehrs know more than I do since I been out of trucking for a few years.
Prior to going into trucking, and afterwards, I have done some retail selling. I ran a Hobby shop via mail order and a retail store when I got out of the Service. It's very hard to make it and you need to be able to support your self and not take pay from the store till your on your feet solid.
You will have to sell least 1000.00 worth a week to make it just paying the bills at the least. The 4 months I had my store, I my biggest sale was 1000.00 and that was 2 days before I shut the doors.
After Trucking I sold at Flea markets and eBay. Still cost arrises and you have to make more to cover all expenses. But it help me survive.
But [pending on where you live, more people will go to walmarts to buy than they will give you a chance. When I had my store, people would travel 16 miles to Wal mart and pay more than stop at my store in the same town as they lived. My home town everyone rather travel to Anderson, SC, or Athens Ga to shop than to shop local, and if they buy local, it's at Walmarts.