When I was in high school I would buy trucks that I could fix issues on then register them and sell them for profit. I worked at Kragen Auto Parts, so I could get a slight discount on parts and anyday I wasn't working after school I would be fixing trucks to sell. I also was starting to build my first toyota so I would build bumpers or whatever anyone else in high school wanted to make side cash. Grated this was in early 2000's so everything was way way way way way way cheaper, BUT i only made $7.75 an hr at my job, so my paychecks would be under $300 for 2 weeks worth of work. So like others say get a better job that will get you decent tips, can't really mow lawns in Gilbert since most homes out in Phoenix Valley have desert landscape, BUT you could start cleaning pools. I paid my pool guy $125 a month and he would come once a week for maybe 45 min. He would sweep the sides of the pool, test strip water every other week to check chlorine level, make sure my chlorine floater had pucks in it, then run the pump to make sure the pressure wasn't too high because the filter's would plug up, which if they were he would notify us on filter replacement OR he could remove and pressure wash them for cheaper BUT they didn't last as long doing that. So find a shop bitch job that you can come in on day's you aren't working at the restaurant to sweep and do odd jobs around the shop for cash or a paycheck, clean pools, fix and flip vehicles (which takes more money up front and has a little higher risk but high return for the hours, as long as you know what the used vehicle market value is and how to fix them and estimate how much to fix them before you buy them).