Tuna pasta salad is very easy:
Make 16oz. of large elbow macaroni. Drain and let dry then douse with very cold water to get the pasta nice and cold, then dump that in your serving bowl. Open a can of tuna, preferably Bumble Bee the extra special good kind they sell. Flake the tuna with a fork as you put it into the pasta in your serving bowl.
Chop up app. half a smaller red onion and but the chopped bits into the pasta and tuna and then add salt and pepper, not too much at this point. Then add three tablespoons of Best Foods or Hellman's mayonnaise. Mix that all together until it's all mixed together, cover, and put in the refrigerator for a few hours. or over night, or whatever.
When you're ready to serve and especially if it's been overnight, then add two more tablespoons of mayo and mix it all thoroughly (if it's not overnight, you're probably fine with one tablespoon of mayo), salt it liberally and then serve. It must be nice and cold so I always recommend overnight. Then those who are eating can add more salt should they desire it - I always do for each serving I eat. That's it.