Dave2005 - welcome to the world of off road! It is addicting so be prepared! Some good advice here already - keep on asking the questions, that is how you learn.
On the clutch as others suggested - worn plates possible, or perhaps your bike's low end power is down for some reason - power valve sticking perhaps? Needs a top end?
I see you are from Michigan. Check out the Michigan Trail riders forum here on DRN - very active bunch there, someone is always willing to hook up for a ride. Introduce yourself! Consider some Family Enduro Series events - great way to meet other Michigan riders, and learn about enduros - these are easy rides, nothing technical, but a blast to do - I have two kids racing the series this year - you can quickly learn the art of enduro time keeping.
A few MIchigan off road FYI's - many of which I am sure you are aware of:
On state land the only place you can ride is on designated ORV trails (unless your bike is plated)
Max noise limit on state land is 94db - that is pretty quiet compared to many MX bikes. Even on private property my opinion is you should keep it down to 94db. Stock KTM 2 stroke off road bikes (ie EXC's like yours) are known to be pretty quiet - which is good!
Spark arrestor is required
ORV sticker required
Enjoy the sport - and do introduce yourself in the Michigan Trail Rider's forum!