You're getting a lot of bad advice here. For starters the IRS doesn't care about your age. At 17 you pay taxes just like the rest of us. If you were to cut grass and only cut grass than you would not need the NJ home improvement license. NO mulch, planting, etc. You can do business as a "DBA" or Doing Business As. You can call it whatever you want. You should research it because you could potentially run into issues with servicemark/trademark infringement. You do this at the county office. Also check the towns you want to work in some require additional registration. You will need to register with the state your DBA so you can collect sales tax and pay your income taxes. You then get your insurance with your DBA. Yes you need to get commercial plates and letter your vehicle also. You might need a cosigner since you are a minor for some things. That is a big risk for someone. The option in all this would be to get a proper business entity through the state which lines you up for a proper business later on, but legally you can DBA and be fine for what you are asking.
You could of course do what you want as well and risk losing your truck, going to jail, or getting your parents sued, etc. I do not recommend it. Of course there are always guys that do this, but at the same time we all hear every summer of the 8 year old's lemonade stand getting shut down by the government because they pissed off the wrong person. Do not think cause you are small or young you are immune to the law or it's enforcers.
Going legit is very easy and does not cost a lot.