Some simple ways. You can get 500N daily by going to noobscraft.com/pmc (While online on the server) and voting for the server.

Otherwise it's typically by selling to the server shop, running a chest shop, or selling to a chest shop.

Check things on the server shop with /shoplist. Or /shopcheck itemname. You can sell items to the shop by having them in your inventory and doing /sell itemname #.

There are a ton of chest shops at the /spawn market, so you go to /spawn, then turn to your right and walk into the shop area. Check the shops for things that people will buy, and you can gain money that way.

You could also run your own chest shop, but it doesn't quickly gain you money from what many people have experienced so it's more of a risk than anything.