If you speak no Spanish at all you’ll want to learn at least a few key words and phrases before coming down as Spanish is the national language of Ecuador. Also, bring a Spanish-English dictionary or app on your phone to help. There are areas where you’ll find more English speaking Ecuadoreans like the Mariscal district in Quito and the touristy areas of Cuenca. Vilcabamba has a high population of expats so you’ll find a lot of English there as well.
With two weeks you could see a nice portion of the Andes or of the Coast. Or if you’d like to see both, I’d recommend picking one location in the mountains and one on the coast and using those as hubs to explore from. From Quito you can take day trips to Otavalo, Cotacachi, and Mindo. From Cuenca you can visit Chordeleg and Las Cajas National Park. If you have the time, Banos is a fun town with hot springs and a lot of outdoor activities and Loja is a nice small colonial city.
Also, check out the “Travel Itineraries” link in the menu bar at the top of the Ecuador Insider page. There are some good suggestions there for different trips through Ecuador.