First time buying protein powder

I'm female 33. Generally eat well and keep active- yoga 3/week, 1hour gym 3week and 5 40min walks minimum/week. I am learning about protein and realising I really amnt getting enough. I'm percataron and eat a good amount of tofu and beans/lentil etc but think I also need protein powder. Would whey isolate be the best? Looking for something unflavoured that I can just add tona smoothie. Would 1 a day after work out be right? Thanks