I've been looking at RCA to HDMI converters such as this one but I don't know if it will work or not.
It'll work, but it's not what you want, and is absolutely not what you need.
All that'll do is digitize your analog composite feed into an HDMI feed, but you still need some way to get the footage into your computer. That HDMI port on the side isn't bidirectional.
Does anyone know the best way for me to transfer the footage to a computer?
You need some kind of capture device. If you can get your hands on a Digital8 camcorder it will have an internal digitizer, and then all you need is a 4-pin-to-9-pin Firewire cable, and, probably, unless your laptop is old enough to have a built-in Firewire port, which I doubt, a Firewire to Thunderbolt adapter. From there iMovie should be able to directly capture the footage straight off the camcorder.
Do not look at Firewire to USB cables, they aren't a real thing, they don't work, they are a complete and total fraud and should be used by nobody.
Alternatively you could look at some kind of USB digitizer, there's a bunch of them out there, just try and avoid any devices with hardware video encoders. Hardware encoders are handy to have in some situations, but the rest of the time they produce inferior results to software options. Hauppauge, Diamond, Dazzle, Blackmagic, AJA, Matrox, Elgato (rebranded Hauppauge with macOS software), AVer, there's a few good brands out there. Most of them come with software, but when shopping around make sure you're not buying a cut-rate "hardware only" package, or if you are, make sure you have software that works with the hardware.
HDMI dip, or this https://www.amazon.com/dp/B01L8GG6PW/ref=cm_sw_r_sms_apa_i_1vSTEbW265KE2
Would using an AV adapter work instead? You could try buying an RCA to HDMI Converter, then plugging the console's RCA cables into the input side of the converter. Then take an HDMI cable and plug one end into the output of the converter and the other end into the HDMI-in side of the elgato. Then take another hdmi cable and plug one end into the HDMI-out side of the elgato, and the other side into your tv.
{EDIT}: Just bought an adapter off Amazon for about $14 and everything is working fine using the method I stated
https://www.amazon.com/gp/product/B01L8GG6PW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
I’ve played with a lot of ‘em. One of the best, I kid you not, was using the UHF coax output on channel 3 and using the TV analog tuner! I have a pretty nice Sony 4K and the built in turner we use all the time for digital channels too. Another plus is it can scale the video to 16:9, if you want.
Second best was using the built in RCA inputs on the television from the VCR. I have an SVHS VCR with SVideo output, and an Amazon converter we tried that looked great, and would have been the best option of all except the VCR would drop the color randomly in the frames. Using a normal VCR with RCA into the device looked OK, nothing special. It’s hard to describe, but I feel like it did a better job of showing the shortcomings of RCA video than recreating the signal for your viewing pleasure.
We have also tried to use a capture device that outputs to HDMI using svideo or RCA and that works pretty good but not the most ideal for playback. It takes great quality video capture though.
Overall, use the direct tuner or inputs in your TV if possible, it seems to do a better job image processing and upscaling if it’s a nice TV. We also got back into Nintendo Wii over Covid (it’s 480p). It looked like crap through the converter with RCA, but with component direct to the TV it looks pretty amazing.
https://www.amazon.com/gp/aw/d/B01L8GG6PW pretty meh, built in will probably work better if you have them.
https://www.amazon.com/gp/aw/d/B083PZTDS9 good output, great capture. Kind of cumbersome to use a routine playback because you need to power it on, switch to video, etc.