First try at container gardening

Hi Everyone!

Im new to the site, and I'm looking for some tips on container gardening. Growing up, we planted straight into the yard, but I have heard that container gardening can be tricky for some veggies and herbs. I have a 3.5ftx 3.5ft- ish planter that I have made from recycled Ikea furniture parts, and plans for other containers as I need them. Im trying to grow black beans, cucumbers, sugar snap peas, summer squash, romaine lettuce, carrots,chives, and a pretty evening sunflower mix. I know the sunflowers are going to go into their own planter/s. But will most of this stuff grow well together or am I looking at having to split most of it up into separate containers? I have plans for a small trellis for the peas, and from what I am reading, possibly one for the cucumbers. That'll take up most of my space in the back of the planter and one side. Should I make something for the summer squash to grow upwards on?

Just looking for some advice on what I can and cant plant together and some ideas on how I need to plan out this garden. We have limited space, as our 'yard' is only a patio, so no digging into the ground is allowed. It ALL has to go into containers.