towing 14' trailer with Ford Ranger?

Sorry, it's not a supercab, just regular... and it's the XLT model.

Can you buy some extra life insurance and list me as the beneficiary?

I could use a little extra money.

It can be done, and I'd say there's not much margin for error, especially if you're wrong about the trailer weight. Experience really helps, and you have none, so that's bad. Trailers have this magic about them that causes wrecks. It's hard to explain what causes it on USENET, but there are dynamics involved that are surprising, and they don't end until you slow down or you wreck. If you look for trailer wreck photos on the internet, you'll see what I mean. They're just wild. A lot of times the trailer goes over the guardrail first, and the tow vehicle is pulled over the rail by the hitch. Just look for some photos and you'll see.

But anyway, to asnwer your question: The weight is no problem, in my opinion. Some arrangements of 3700 lbs will be very easy to control, and some will be impossible to control. Experienced towers will know what I mean. You'll want to go good and slow until you figure out what it all feels like. The more that weight is concentrated in the middle of the trailer, the easier it is to control its direction. If the same weight is spread out, it becomes harder to force it to turn.

You'll want about 400 lb on the hitch. I'm sure you won't have a trailer scale, so make darn sure the trucks squats a little when the trailer is on. Maybe 2 inches. This will take weight off the front of the truck, and the front wheels will slide in an emergency. You'll just have to live with that. Don't get in an emergency. That's how everybody else does it. When the center of gravity of the trailer is just in front of the axles, resulting in slight weight on the hitch, trailer swaying will tend to dampen itself a bit. You may need that.