Do bell pepper plants live through the winter? I live in Portland, Oregon.
They will not survive outside, but you may be able to overwinter them indoors. Here are directions: https://www.gardeningknowhow.com/edible/vegetables/pepper/overwintering-peppers.htm
Will my red bell pepper plants from this year come back next year or do I need to start new ones?
They are annuals in most parts of the world, so you will need to start new ones next year.
Can you grow bell peppers near corn? What are companion vegetables for bell peppers?
This article will help you:
https://www.gardeningknowhow.com/edible/vegetables/vgen/companion-vegetable-garden.htm
How tall do the bell pepper plants get, and should they be kept pruned?
They normally don't get much higher than 4 feet tall. Some people do prune them, but they do not need to be pruned. Here is some information on it:
https://www.gardeningknowhow.com/edible/vegetables/pepper/pruning-bell-peppers.htm
I currently have bell peppers, summer squash, and a tomato plant in my patio garden. I want to know if they can survive in pots or if they need to be planted in the ground.
The peppers and tomatoes do well in pots. Squash plants can be grown in pots, but they need a lot of water, so make sure that you are giving them enough water to grow well.
I have also grown tomatoes in pots, had a good crop last summer, watering well essential.
How long do I have to dry out fresh seeds before I can plant them?
You don't need to dry the seeds to grow them. You only need to dry them if you plan on storing them. You can plant them as soon as they come out of the pepper.
I saved some seed from early bell peppers this year. I have dried them but am not sure that I should plant them this year. Is it prosperous to plant seeds from same year crop? I know my grandmother always kept her seeds for future use but don't remember how she stored them or in which season she planted them. How do I store the seeds for future use? Or-- do I not even attempt it?
If you live in an area where you have a full growing season ahead of you, there is no problem with planting the seeds now.
If you do not have a full growing season ahead right now, you can store the seeds for the next growing season by placing them in a paper envelop, which can be placed in a plastic bag or tupperware container and then this can be placed in the veggie drawer of your fridge. You can store them this way until you are ready to plant and pepper seeds remain viable for many years when stored this way.