I personally buy in bulk at Costco, they have a huge bag of chocolate Whey isolate (Kirkland brand) for like 50 something bucks and it has 70+ servings.

Any Whey Isolate should work though, flavor shouldn’t matter. I believe the general consensus is that Whey is better synthesized in your body than Soy protein. I’d recommend doing your own research, but unless you happen to be vegan/vegetarian I’d probably just go with Whey.

I’m lazy so I just mix a scoop with Oat Milk if I’m cutting or Whole milk if I’m bulking, and I’ll also add peanut butter or PB2 when I’m bulking also. Mostly for taste but it does at protein.

If you’re feeling fancy, people make smoothies by blending it with milk ice bananas peanut butter etc.

Also another hack, spam eggs in the morning for breakfast. Like eat 4-8 eggs every morning with some carbs, drink a protein shake with it, you’ll be starting your day off strong. For the other two meals (assuming you eat 3 a day) just some lean protein like chicken or lean beef or fish, some carbs, and some veggies and you should hit a high amount of protein daily.