I cannot get my eu2000i generator to start, for I cannot get ant spark to spark plug.

Check oil and the low oil switch. Pull wire off and see if it will start.

What will that mean, a bad oil switch?

Usually ignition systems get grounded to shut the engine down.

Thus a low oil level or a defective switch can cause no spark. So can a bad ignition module/coil. Rust on the flywheel can do it too where there is no gap for the magneto. The controller could shut the engine down too. Would need a link to the manual to try to go further.

These are a few simple things.