Unfortunately voice activation is not a basic thing in phones. Requires iOS or Android’s equivalent. Figure out which one you like, then buy the cheapest phone that has it. Best Buy is traditionally where to go for the best deals on phones.

With my vision, I always wanted a phablet..I'd just carry a tablet like a phone all the time. I have one of those ZTE Obamaphones, and it's so poor, voice recognition works 30%, Google Assistant stutters, which is a scary thing in maps sometimes. Most terrifying phone to have when nearly blind. I miss the palm pilot way of typing haha.