Quoted from FatPanda:

Pinball machines generally require very little, if any lubricant. If it's not obvious, no WD-40 anywhere near the game. If the game needs to stay off because of issues, you should leave it off until it gets fixed properly. The last thing you need is for you to volunteer to maintain a machine, have a coil lock on because a shortcut was taken to allow the kids to play it, then have a fire on your hands. Obviously, that is the worst case scenario. It sounds like there's still a lot for you to learn, which is great, but I would advise against taking any shortcuts or "jury-rigging."
Please don't let my post discourage you from continuing, but I saw some red flags in your post and wanted to make sure that you learned the proper steps before proceeding.

Quoted from FatPanda:

You'll find that old or new, pinball really hasn't changed in the last 40 years. A game that you work on from 1975 will have generally the same mechanical principles to 2019. A flipper mech generally operates the same; a saucer kickout generally operates the same. Most games will benefit from cleaning the mechs and re-sleeving the coils. If you want it "just good enough" for the kids to flip the ball, you might not have to do a full shop job. For me, any game that I work on gets at minimum, a new set of rings, clean/waxed playfield, LEDs, rebuilt pop bumpers and flippers, cleaned and resleeved mechs (basically anything that is a moving part), new drop targets or other plastic parts. Obviously, for a game that you don't own, the amount of money/effort might be different.
You'll find that the cost of a complete shop job could range from $100-$400 or more. Just depends on how well you want to present the game and how well you want it to play.
For your other issue with the saucer kickout, going with chuckwurt advice will likely get that kickout working properly again.