That, unfortunately, is going to have to be trial and error, especially until you learn to play with the EQ and compressors. So whatever works, works. I’m sure you’ll get the hang of it in no time! 
It’s called Logic Studio and it is a fantastic program, probably the best in the world, for creating sounds. Problem is, nobody seems to know how to use it and it has a mind of its own. If you can get past the interface and all the tricks and whistles, there’s some real power under the hood.
Logic Studio comes with full orchestra recordings of most instruments for each note and velocity so it really has superb plugins. Considering what it can do, the cost is very low so I highly recommend it but that said, I used to use Fruity Loops before I switched over (unfortunately, they aren’t transferrable that I know of). There are some fantastic soundfonts for FL10. Especially for horns and strings. I remember a friend of mine having a library of like 800 soundfonts he found somewhere online…?
If you’re willing to do some digging, you can have a pretty impressive library. Don’t feel constrained. It’s just going to take some leg work!