Take the stock off and clean all the visible chinese mystery oil off. Clean the barrel then just start shooting

Don't be surprised when the thing actually shoots darn nice right outa the box with nice groupings.

You don't have to tune it right away,,, just shoot it,,,, it'll be just fine.
As for the scope,,,, Even with a high mount if you use a scope where the objective lens extends over the loading port you're gonna have trouble loading a pellet. Do yourself a favor,,,, find a scope and mount combination where the objective lens stops behind the loading port.
I have 3 of these rifles and I put very simple, short 4x32 scopes on my guns and they work great.
They are great little shooters,, you're gonna have a blast with them....
Jeff