I did a long reply and the internet dropped out, I can't do it all again.
There are misconceptions on here. Do read the manual and ask your instructor.
A few quick points, I won't launch into the long post I had.
Best glide is for range. It varies with weight but this is insignificant over small weight ranges. If your aircraft has one speed published, use that. If it has speeds for different weights, use the speed for the weight you are at.
If flying into a headwind you may need to increase glide speed. (If you glide at 65 knots and are gliding into a 65 knot headwind, you won't make your field).
Maydays and pax briefs are if you have time only. Aviate first. Your pax will know what is going on. Groundloop rather than hitting anything.
Engines DO stop without catastrophic failure, eg doing aeros. You can't use the starter if the prop is windmilling. Set it up and it should start. If that doesn't work and there is time you can stop the prop by hauling the nose up, then try the starter, but if that doesn't work the option is an air start (dive) which requires a lot of height, speed, and pulling out of a dive.
Prec searches take a lot of time, probably 20 mins after you've found your field, so don't leave things until the last minute. You might not have time to do all the passes you would like, maybe just one or 2 passes. Doing a pass at 20 feet has dangers as there could be a single wire down there. Better to stay above wire height, and if you see a wire when landing you can duck under it.
I won't go into the length I'd written previously!