Do you have access to used tyres? They make a great potato tower. Best wedged into a corner, stack them up 3-4 deep (or 1 cars worth) and fill with compost. Plant a couple of potatoes in and away you go!
The important thing is the shape of your container. Straight sided or wide bottomed is best, for deep rooted plants. They're much more stable and available in a huge variety of designs and materials. Bedding stuff with shallower roots can live in smaller, wide topped pots quite happily.
Those terracotta pots with holes in the sides are OK after a fashion, but I've always had problems with mine. The bottom holes don't seem to do so well. I suspect it's the weight of the soil compacting it down. I would suggest you don't use the same compost every year but empty it out once the strawbs have finished and put a draining layer of gravel half way down when you refil.
Tomatoes do fine in growbags, as did the courgette plant I had one year, although that did start to ramble down the garden path at an alarming rate. There are some varieties of soft fruits now, particularly raspberries and loganberries, that can be pot grown. Peas will do well against a wall or fence or along a balcony, but they need pretty deep and well composted earth and are mostly not worth the effort - unless you get a bumper harvest, you only get a couple of meals worth out of them. Runner beans are fun and pretty, but the same planting applies.
As with everything, the secret is regular watering and not allowing the compost to dry out - certain composts when dried almost never retain water in the same quantities again.