I'm on 4.4 US. I heard HBL only works on 9.0-9.2? But what if I update my emuNAND to 9.2? I recall having the Homebrew Channel on my Wii, I just don't know if I need it or not for my 3DS. And if I should get it, how will it work alongside autoboot/coldboot?
HBL works from 4.0.0-7 to 10.3.0-28.
I believe ninjhax works from 4.0.0-7 to 9.2.0-20, so if you have Cubic Ninja, you would be able to use that. But that is your only entry point if you are under 9.0
9.0 or above, every other entry point is also available. Smashhax only for New 3DS, browserhax only for 10.1 and under (9.9-10.1 only for New 3DS unless you were able to block the update nag on O3DS), menuhax only for 9.0-10.1
As it stands, you don't really have an advantage for staying on 4.4 sysnand. You have all the reasons in the world to update it to 9.2, so you can autoboot.
You could update your emunand, or you could leave it as-is. It's recommended you update it, there are only advantages to keeping emunand on latest version as of right now (10.3)
You should be able to access every entry point on latest emunand version, apart from browserhax and menuhax. It's a lot easier to use yellows8's homebrew launcher loader, though, so I recommend that.
You only really need Homebrew Launcher if you want to use homebrew in .3dsx format, by the way.
(You did mean update your sysnand to 9.2, right? and not emunand?)
When you have sysnand at 9.0-9.2 and can autoboot, install menuhax, and then open your menuhax ropbin payload in a hex editor. Search for text-string "boot.3dsx" and rename it to something else (anything works as long as it's 4-characters long, personally I use nhax.3dsx) Then rename your CtrBootManager to the same name as you typed when you hex edited your payload. That way, when you start up your 3DS, it will, for example, load nhax.3dsx rather than boot.3dsx
Then when you have yellows8's HBL loader installed, the payload for that will load boot.3dsx as normal, so your menuhax autoboot cfw won't interfere with homebrew launcher on emunand.