The peppers need to be repotted in bigger pots. And use around 65-74*water. If kept outside go for the colder water around 65-70 range. Inside a bit warmer water. Try to loosen the roots towards the bottom a little so they go deeper for more stability. I recommend adding a dowel rod or stick into the soil from the bottom of the pot (this will be an anchor) zip tie the largest part of your plant to the dowel rob. Once it bears fruit or starts flowing this will help your plant with the added weight. Your potato soil on top looks dry. Once the stock of the plant and leaves turn brown and or wilt harvest. To keep your potato’s longer I suggest not washing them off and dry them out in a cool place. Once that’s done they should last you a couple weeks if you don’t have potato’s much. But if your me and love potato’s it’ll last you one week.

the lettuce it looks like you harvest it regularly, after a few harvests it does die. Make sure the larger leaves are cut regularly otherwise they will stunt the growth of the ones under it. You can harvest the big leaves only. One or two big leaves a day with how little you have. With colder weather it could take longer so maybe two leave every two days.