The drain plug is in the bottom of the oil pan.
There is a sight glass in the front that you can see the oil level through to check it.
Depends on what oiling system you have as far as the filter. If you can't see the filter underneath the headers or in front of the clutch cover mounted to the chassis, then chances are you may still have the motorcycle filter set up, which would put the filter on the rear of the engine.
Is this a new engine?
Send pictures to jim@vmsmotorsports.com and I will try to help you out
Jim