Beans and whole grains tend to have the most protein, and product made from them, such as tofu or tempeh. You can also buy mock-meats made from isolated or refined plant protein, and those tend to be higher in protein as well.
Most plant foods have some amount of protein in them. Even foods like mushrooms or broccoli have a fair amount of protein relative to their total calories. As long as you are eating a variety of foods in sufficient amounts, you should get enough protein. I would only recommend worrying about protein if you are on a calorie-restricted diet, or you're raising kids or recovering from an injury or surgery.
Beans have other benefits, such as being associated with bone and gut health, and populations that consume alot of beans tend to live longer than those that eat fewer beans. So it's good to include beans every day in a vegetarian or vegan diet.