I add whey protein to my smoothies everyday, to my oatmeal in the morning with berries, and it is easy to add to many other things depending on flavor that you get. (Start with vanilla since it goes with most things easily). Health food stores have it for body builders, but Walmart sells two brands at the best prices. Consumers Union which tests health food claims and supplements for actual content recommends 6 Star brand which Walmart has for about 20 bucks.
With your cholesterol issue, you want to be conscious of where your protein is coming from, but there are plenty of sources that shouldn't make that worse if you are disciplined about what you choose.
As to protein consumption you should shoot for about 1/2 gram of protein per pound of body weight minimum per day to start. I can get about half my daily need from oral consumption of eggs, fish, nut spreads and humus that I make in my Vitamix, and other sources, but I need the whey protein to make the mark of total needed.
Note there is a new study out that is related to the loss of muscle mass from aging -Sarcopenia (I'm well into this process) and it speaks to the benefits of doubling up on protein intake. Please note that proteins alone will not help with all this is you are really sedentary. But even moderate exercise and activity will help put a modest about of muscle mass on, if you are consistent with it.
http://www.sciencedaily.com/releases/2015/01/150130121613.htmIn the right column of this page there are other stories about protein and muscle that you may find interesting.
