does anybody have any tips to share about their Madagascar visit?

I will be there to buy some contemporary art and to deliver a variety of art materials to a school for the needy

Will likely visit one of the national parks and make a few outings from the Capital city.

Hi! That sounds like a wonderful trip. For visiting national parks near the capital, Andasibe-Mantadia is a great choice, easy to reach and full of amazing wildlife. For outings from Antananarivo, you can explore local markets and cultural spots too.
Enjoy your time in Madagascar and all the best with your art project!