Voltage regulator from 24v to 3.7v
For the reasons outlined by WhatRoughBeast, resistors are a very bad idea for voltage regulation.

For "realistic" DC-DC voltage regulation options, there are two, and only one is really feasible for your application:


Linear voltage regulator
DC-DC switching regulator


The first option, a linear regulator, is typically an integrated semiconductor device in a transistor-style package. In simple terms these devices drop excess voltage above the regulation voltage as heat across a semiconductor junction. Linear regulators are very easy to use - you connect the supply pin, the output pin, and a common ground, and you're off to the races. They also provide low ripple.

The problem with linear regulators is that you're dropping a voltage across a junction that a current is passing through - ie: all that power is wasted as heat. If you don't draw much power to begin with and your supply voltage is not much higher than your regulation voltage (for example: 5V to 3.3V), this isn't a big deal.

In your application this will be a problem though. Your power loss is equal to your current times the difference between the supply and output voltages:

\$P_{loss}= I_{load}\left ( V_{in} - V_{out} \right )=2A \left (24V-3.7V \right)=38.6W\$

That's almost 40W of heat you're dissipating in the regulator. That's some serious cooling required!

Instead, you'll need to use a DC-DC switching regulator. These devices use an inductor as a temporary energy storage device which is switched out very quickly. They do generate more noise and are more fiddly to set up than a linear regulator, but are typically 90% efficient at power conversion. They also have the advantage of being able to increase voltage (boost converter) as well as decrease it (buck converter). Some types (buck-boost) will do both in the same device, and other types can provide a negative voltage rail.

I find this video series from TI is really good at explaining the fundamentals of how and why they work. To actually implement one, you have a couple options.

Many companies sell easy-to-use finished modules, sometimes referred to as "linear regulator replacements." The advantage to these is that they're just as easy to use as a linear regulator, and some even come in industrial-friendly enclosures with screw terminals if you're adverse to making a PCB. The downside to these is that they're usually pretty expensive, especially for higher current output.

The other option is to buy a switching regulator chip and add all the external components (at minimum a diode, inductor, two filter capacitors, a resistor divider for feedback, and sometimes a MOSFET). This usually isn't too hard, but the design is a bit more interactive. Most manufacturers provide pretty good datasheets which outline the design process, part recommendations, and preferred PCB layout. If you deviate from these, make sure to simulate the design. Other than more work for design, the other disadvantage is that you will need to do a PCB (switching noise makes switched devices infeasible for breadboard construction).

Good luck with your project!