How to market a language school?

Hey everyone, I have an idea of starting an online Swahili language school, with the intention of having an office space for offline classes once things get rolling. I’ve thought about my ideal customer, my niche in the industry, and where I’ll be doing business (Mombasa, Kenya), but how would I actually market my business to reach prospects? My primary target markets are 25-60 year old American/European expats and travelers in Kenya (or those who have an interest in going to Kenya). How would I go about reaching this demographic through online marketing?