I learned on 1967 vintage -140s, so maybe I can add my tuppence. If it is a one mag start, it will be the left mag.
You should not have any trouble getting in, so long as you touch down accurately.
The -140 tends to sit down when you cut the power, so make sure you get the yoke well back to protect the nosewheel... but as a tail dragger pilot, I'm sure that you would anyway.
Before you fly, you might wish to try the yoke full back and note that (a) it comes back a long way and you MAY need to pull it back this far and (b) towards the end of the travel, the yoke moves up, towards your chest .. feels a bit wierd if you're not used to it.
If it is an old -140, it might have plunger engine controls, like a Cessna, but no vernier adjustments - the mixture plunger is tiny and it has been known for new pilots to type to mistake it for the carb heat
These (and other posters) minor points apart, the Cherokee is a very docile mount.