All you need to get started is any kind of non degradable container, depending on what you want to grow, ie, a plastic bin, large food containers like cottage cheese or soft butter spreads come in.
I had several of those large plastic bins that slide under the bed and the deeper ones from Wally World, redwood planters that look like half barrels and have used 2 and 3 liter soda bottles (https://www.instructables.com/id/Go_Green_Upside_Down_Hanging_Planters/
) and made a hanging herb garden on my patio! You need to determine container size by root depth and recommended spacing.
Get some potting mix, compost if you need it, garden bark or some kind of filler that won't pack down, pre-started plants or seeds, and a cardboard roll from either, toilet tissue, paper towels or gift wrap, depending on how deep your container is.