My name is Sahar, I love gardening but not that successful in it

I have a bonsai and I leave in Medellin, weather temperature between 17-25 celsius all year round. My little bonsai seems to be dying. I do not know what type of pine is this, cause as I was reading this forum depend on that I should decide on watering of the plant. Could you help me on:
1)figuring out what type of pine is this? and how much water it needs?
I have been reading the forum post on yellowing leaves. Water: My pine soil as you see is hydrated, there are many little green grasses growing on it. so I don't think that's it. Light: I tried putting it inside in a soft light and in the balcony where it can get 2-3 hours direct sunshine a day. Insects: not an expert but I can not see anything on it. none of them worked. watering too much? I'm scared to take it out of pot as I know it may even hurt the plan more.
2)do you have any suggestion on why it is looking like this?
3)only thing I haven't tried is Fertilizers: what type of fertilizers do you suggest for this type of pine and for this specific issue? as you see is very small how much should be the quantity.
I really hope my beauty gets back to life. Help plzzz!!
Any suggestions or comments are welcomed.
Thanks a lot!!!