That appears to be either a ficus microcarpa or a ficus benjamina. You did everything right when you got the bonsai: take off the packaging rocks and move it out of the pot. Good job! It is a tropical plant, so keep the soil moist, but not sopping. A humidity tray is also helpful when working with tropicals. It looks like a great clump style bonsai specimen, and I'm looking forward to see what you do with it. Good luck!

It's definitely not a benjamina, just to clarify. Weeping figs never produce those roots. This is definitely a microcarpa.

The leaves are a bit big to be aesthetically pleasing. I'd suggest partial defoliation...but, as was suggested to me previously, wait until next summer.

It is NOT necessary to wait for spring/summer to trim/defoliate/re-pot a tropical. It can be done any time of the year.

It can be done any time of the year, but the tree responds best when you wait until it is in its prime growing season. By the way, you can even cut straight across the widest part of the "potato" and make a large cutting out of it if you have the guts. New roots will spring out at the edges and you have the beginnings of an advanced nebari.