Fishing is a great way to get gold even if you just stick to the free lure.
Grow Dandelions in your dorm planters,(replant the seeds your free seed gives you) you can even feed the excess seeds to your pet, you will usually get gold, and or gold and TC. You can then sell the TC's you do not want to use.
Silver Chests are a bit tricky and don't give a lot at first, but hunt them down and try to crack their code. Good Luck