I personally found it quite a confusing topic without looking at it in a more rigorous way.
Enthalpy is defined as H = U + pV, where U is the internal (i.e. total) energy. It definitely isn't total energy, although in many circumstances βH = βU and enthalpy is easier to measure directly (it's so useful in chemistry because βH = βU at constant pressure, and experiments done in an open container are at constant pressure).
It requires some manipulation of their definitions to show that for systems at constant temperature and pressure, Gibbs energy is the amount of energy that can do work. If you're going to do more chemistry later, it'll come up! I'd wait until then to look at the whole topic properly.