A 110 can hold a thriving community.
In a tank that size, you should get a mid sized external filter, as they are easier to clean when required.
You will need a heater. They are usually rated to the size of a tank when you purchase them. Just buy something with a rating slightly higher than your own tank size.
Speak to the local fish shop, and ask them what they use to cycle their tanks, and ask them for advice on doing a "fish in cycle".
This is a way of getting the tank going with the bacteria is needs to keep the water clean. You can also ask them for some "filter media" from an established tank to help speed up the process.
A carefully managed fish in cycle is perfectly safe for fish, provided the necessary water changes are maintained for the first couple of weeks, especially when feeding lightly and using established filter media in with the new media in the filter. Even just hanging some used gravel from another tank in the foot of an old pair of tights will have a similar effect.