Salad stuff can also be prepped many days in advance. However, now would be a good time to mention how important it is to have a sharp knife. First of all, if it far safer to use a sharp knife. Most people are afraid to use a sharp knife because it seems more dangerous. But, when you use a dull knife you have to exert far more force, which makes it much more likely for your knife to slip and more likely for the knife to be substantially out of control when you do slip. So have a sharp knife!
The other reason to have a sharp knife is that it allows you to prep food that will last longer. When cutting vegetables the goal is to have a nice, clean cut which damages as few of the cells as possible. A dull knife rips the cells open, leaves a jagged edge, and spills the cells contents (mostly water) out which dramatically decreases shelf life. With a sharp knife, a fresh pepper will likely last 7-10 days if you place a paper towel underneath them in the container or bag.
There are tons of ways to cut a pepper, I find the following the easiest. I take the top and bottom off, pull the insides out, slice down the side to open it into a flat rectangle, then slice off any extra ribs of “pith.” Then it’s just a matter of slicing or dicing.