Personally, I never use medications on flights.

In the unlikely event that something does happen I want my wits about me.

I may have 1 alcoholic drink... but that is the limit.

If you are going to be alone there will be no one else looking out for you so
all the more reason to keep your wits.

Pack light as possible and start assembling your items / packing list now.
Review each item critically considering "do I really need this?".

If you will be checking a bag keep in mind there is a chance it may end up
lost along the way... and you may only be reunited later or never. Bring a
carry-on with some basics to get you by for a day or two until you are
reunited or secure replacement items. Place information about your itinerary
and how to contact you in checked luggage.

No electronics or high-value items in checked luggage. Leave at home or
keep with you in carry-on.

Review each airline site for what is acceptable as carry-on / checked so
you don't end up fumbling somewhere along the way.

Review TSA site for what is acceptable in carry-on / checked luggage and
the procedures at the checkpoints. Consider going through with empty
pockets and only your ID (Passport) and boarding passes in hand.

Above all... enjoy the experience! It will be an adventure!