Hello and welcome.
Plenty of others better qualified than I will advise re instruments etc. However, I am left-handed, so I will comment on your latter point.
By 'left-handed' do you mean that everything you do has to be oriented to left-handedness? Although I write left-handed etc, I play standard 'right-handed' musical instruments (viols, cello, sax, piano) without any modification whatsoever. With string instruments, it's an advantage as I have dexterity in the fingering hand.
If you seriously think that you need a left-handed instrument, one with all of the keying completely switched around, then I imagine you will be in a world of pain and expense.
I think you should probably see a teacher before you look at buying and have a session checking that out (some teachers will have spare instruments you would be able to use on a short term basis).
Personally, I think you will find holding a standard instrument will be fine and not an issue at all