How is the best way to render a video with the minimum loss of quality and time?

My own approach is to render an archival copy first. Usually a higher end codec or near lossless. Like a QT PRO file etc. Once I have that, I then setup my final encodes to export from Media Encoder. Or the like. While I have and sometimes do render final codec output at the onset ... I usually like to compress/render the master file to create the final versions. It moves quicker. It gives you a speed boost as the system doesn't need to render the layers, pulg-ins, FX, etc. each time you render a new video. Lastly, if your end result is YouTube ... you CAN upload the master file, depending on your bandwidth for internet upload, etc. it can take a while. BUT ... your video will look a lot better as YouTube will and does re-encode on their end. Not sure if any of this helps.

Something helpful is to match the export settings to wherever your intentions of posting is.

The quality will depend on your export settings - you can do some quick research based on the platform that will host your video on what settings it should have to live there. As to time, I feel ya, it often takes a couple of hours. Best advice I can offer is to do it right before you leave work for the day, and make sure every other program on your machine is closed. It takes a ton of processing power to export a video, so your computer will need to "focus" solely on that.

It sounds like you're battling with inadequate hardware, and you won't improve render times significantly without upgrading. Rendering video uses a lot of CPU and memory, so the more cores you have and the more RAM, the faster things will go. A mechanical hard drive will also slow things down considerably. To give you a comparison, a 10-minute video renders in 3 to 4 minutes on my desktop machine, which has a Core i9 9900K (8 cores/16 threads), 64GB of RAM, and runs all files from NVMe and SATA SSD drives. Meanwhile, you can use Adobe Media Encoder to render in the background, so you may be able to go on using the machine for other things while it renders in the background. I'd suggest getting your edit the way you want it and render overnight. At least you won't have to sit watching the machine crawl through the render process.