Is the bike i'm using right for Mountain Biking?
Looking at the component specs, its an entry level MTB, one better than a BSO. 

80% of mountain biking is about the rider and his skills, not the bike. Shops won't tell you this, as telling you your riding skills matter most does not end in a sale of a newer season/more expensive bike.  Cashed up middle aged execs won't either - many just want you to see how much money they have to spend on toys and cannot ride to save themselves - a lighter/faster/more forgiving bike hides the lack of skill. Competitive riders care what they ride - they have expensive bikes because 1/2 a second here and there makes a difference to them. 

Where it will let you down is weight (Makes it harder to accelerate and not as fast up hills), front forks (Likely to have poor rebound control and bounce a lot - pogo sticks) and gear shifts will not be fast and crisp.  Picking the right gears early will be critical to having fun, as will picking good lines in corners.  The forks mean you will not have room for cornering mistakes and will probably have to enter corners slower than other.  Being a hard tail, you will need better skills to ride fast, as they are less forgiving of mistakes than a softtail.  It will also need more maintenance and tuning than a better bike, and probably wear out faster. 

As far as trails you can ride - if the trail requires air time, the bike is not great. It would be OK on trail that can be ridden without having to do jumps, but is better suited to XC style trails rather than all mountain or down hill.   

In the end, you won't break it any quicker than a better bike, so go out and have as much fun as you can on it.