Needing Gardening Advice...

I want to plant a small garden this spring, probably in containers since I rent. I have never done a garden on my own. does anyone know when to start planting? I want to do this as organic as possible, no pesticides, no gmo seeds, and I am going to try to get organic soil and a water filter (im on city water). I just want to plant things I know we will eat, but Id like to do a companion garden to keep down on the bugs and such. has anyone done a container garden or a companion garden? fruits and veggies are expensive if you by organic and if you don't buy organic they are cheaper but really aren't all that healthy (they wear hazmat type suits when they spray crops if that tells you anything) I want to better my health and the health of my family and save a lil money on groceries to get caught up on bills. plus it never hurts to learn to be more self sufficient. any advice will be appreciated :)
What you can grow and when to plant will depend your climate so you need to look for some local(ish) information of give some information as to where you are. My own (UK) first planting task which I'll do some time in February will be to start the Auberigine/egg plants and the sweet peppers growing indoors. I'll transfer them (and the tomatoes which I'll sow after the aubergines etc. are in flower pots) at the start of May. I use May as a sort of turning point for planting things outside too. It's the point where I'd say the risk of frosts should have past.

We don't do companion planting in any serious way but we do grow French Marigolds (Tagates patula) which are reckoned to be a good companion to a good variety of other plants in our veg plot. We like "Safari Mix".
A lot of the seed packets you find in stores will have the information you need to start planting them: when to plant, how to plant them, etc. Even if you don't buy the seed packet, you can always write down the information for later use. As far as companion planting, I've never done that before. But there are ways that you can do organic "pesticides", like cutting a grapefruit in half, hollowing it out (leaving a little of the fleshy part), and placing the hollowed out halves upside down on top of the soil. This will trap slugs. Every morning check the grapefruit halves to see if there are any slugs. If so, fill a small bucket with salty water, then pick up the slugs and put them in the salt water.