How to start?

Here you have 2 options: Klipper or OctoPrint.

Remote monitoring additions

Camera

Go for Logitech C270 (1280x720) or Logitech C920 (FHD). These 2 have greatest number of available printed mods, I think C270 even more that C920. IMO C270 is more than enough for job monitoring.

Sonic Pad

Sonic Pad is Creality T800 AllWinner tablet with preinstalled and customized Klipper. The OS is pretty much closed (even if rooted) and does not allow for any modifications outside what can be seen in the webUI (no KAMP, no Telegram bot, nothing).

The only plus I currently see in owning one is that it has device specific configurations that community is currently struggling to replicate (such as pytouch_v2 implementation - note there is a pytouch_v1 working version of klipper).

Does it work? Yes. Do you need it? That depends. You can refer to the table below.

+ + +	- - -
Creality customized profiles	Closed OS
No in-depth klipper knowledge required	No Klipper addons/plugins
Simple to use from touch screen	Device is slow
Easy calibration from the UI	Touch screens seems laggy
Adds WiFi capability to the printer	Requires separate serial cable to connect to V3 SE
Built-in G-Sensor calibration	Slicer profiles may not have compatibile commands

You can buy one here: Aliexpress. My purchase from the link above came with serial cable and G-Sensor however it was noted that not all boxes had these cables included. Links to these cables is listed above.