I basically have an OG switch with 6.2 on it and was wondering where an end all tutorial was for bootloaders
I recommend
this tutorial, but if you plan on using an emuNAND, you should use
this tutorial.
If you don't plan on using online play, you probably don't need an emuNAND.
cuz I know theres no coldboot mod for my firmware atleast at this time right?
There have been no untethered coldboot exploits released for the Switch, not counting modchips that automatically push fusee gelee payloads to unpatched systems with AutoRCM installed.
Currently, your only option on 6.2.0 (on an unpatched system) is fusee gelee, which requires you to a.) enter RCM at least once using a jig, and b.) push a fusee gelee payload from your computer using a USB connection. After that, you can either install AutoRCM so your Switch coldboots into RCM everytime, or you can continue to use a jig each time you want to enter RCM. Regardless of which you pick, once you load CFW, you should keep your Switch in sleep mode whenever it's not being used, and you will rarely have to enter RCM.
You can also make pushing fusee payloads more convenient by using an Android phone over a USB connection or a cheap USB dongle.
Anything on 4.0.0 and higher is highly unlikely to ever receive an untethered coldboot exploit. Aside from fusee gelee, the best you can probably hope for on 6.2.0 is a warmboot browser exploit sometime in the distant future.
On unpatched systems, fusee gelee works regardless of system version and cannot be patched. If you want to update, you just have to make sure CFW has been updated to be compatible with the new system version. The latest system version is 8.1.0, and CFW is compatible.
and no way to downgrade without some sort of backup?
The Switch uses fuses as an anti-downgrade mechanism. When you boot the Switch after updating the system version, fuses get irreparably burnt. If you try to downgrade after that, the fuse count will be higher than expected, and the Switch will refuse to boot. If a user installs AutoRCM during an update, the Switch will never be able to boot without a custom bootloader like fusee-primary or Hekate, and the fuse count will be preserved. This is what allows downgrades, and a NAND backup isn't required for a downgrade.
In a nutshell, you cannot downgrade to anything below 6.2.0 unless you preserved your fuses with AutoRCM before you updated to 6.2.0.
just wanna run some emus...gamecube Mario sunshine sounds amazing please someone tell me that's possible now?
There are plenty of emulators available for the Switch. I'm pretty sure Mario Sunshine runes fine on L4T Lakka.