Are you flying at a club? If so somebody there can likely help you tune the engine. Do you have an instructor?

The goop you are seeing is the oil from the fuel. it is normal to have some all over your plane after a flight. It sounds like the engine is rich though (too much fuel/too little air). If you have the .46 FXi with the limiter on the high speed needle, pull the limiter off. Adjust the high speed needle a couple clicks at a time until you get maximum RPM at wide open throttle. Then richen it slightly by turning it 2-3 clicks counter-clockwise until there is a very slight RPM drop. Next comes the low speed needle. This is the small screw in the center of the throttle arm. I would turn it in or out (usually in) 1/4 turn at a time until you get a reliable idle and good throttle transition.

Since you are new to this, I would really advise getting help from someone at your field. Make sure the plane is properly secured when tuning the engine and keep your fingers, clothing, tools, etc. out of the prop. It's easy to let a running plane get loose and hurt somebody if you aren't careful.

Once you have the engine adjusted well and it is broken in you should rarely have to touch the needles again unless there is a pretty big weather change or you switch fuels.