Hi and welcome. Well done!
I was a GV rollie smoker (only about 6-8 a day with filter) and I started on 6mg and 12mg. I was chain vaping so went to 18mg and tried some 24mg. Way too strong for me. I was still trying to chain vape but getting sick so now I am a happy vaper at 6 or 12 mg and I cane vape away until my little black heart's content
It's all trial and error but you will find a strength to suit you.