It looks like Ficus benjamina, though its hard to be sure of scale in terms of size of the leaves from the photo - image and info here https://en.m.wikipedia.org/wiki/Ficus_benjamina. Your plant doesn't look like a bonsai, it just looks like a Ficus benjamina that's lost some of its leaves, but instructions as to how to make a bonsai from this plant can be found here http://guide.makebonsai.com/bonsai_species_guide_training.asp?SpeciesID=5018
There is another, much smaller leaved version of this plant which is very similar, and would likely be more suitable for bonsai, and that is Ficus benjamina 'Too Little', image here so you can compare leaf size https://www.rareflora.com/ficusben2lil.htm
This is a Ficus, A Benjamima I think. This is suitable for inside as it is semi tropical. You must repot this tree, buy a packet of Bonsai soil mix and add some gravel , gravel is essential to let the soil drain , a little bark chips would help. Get a pot which you fill to just below the rim , otherwise excess water will lie in the pot and start to rot the roots. Luckily this species does not mild getting dry from time to time. But it must have lots of light , a light bulb is not enough. Put it by a bright window. The bathroom is ideal as this plant likes moist air. Outside Bonsais are easier as they get Moisture, strong light , and fresh air , and rain for free. Never let your Bonsai dry out . Good luck.