Im getting me a 2ds to put luma on it should be version 10.2 or 10.2 or lower i do not update the system cause it be 11.3 which cant be customed or can i update it fresh out the box
And ONLY follow 3ds.guide! Do NOT, under ANY circumstances, go to YouTube, a LOT of videos are outdated or link to their own files, which may contain (often does) their console-specific stuff which will brick other consoles

Side question, sorry op. I'm on Luna +a9lh, is it safe to update to 11.3?