Strawberries?

I have multiple strawberry plants, maybe about 15 on my allotment. I have about 5 red strawberries. the rest are either green, or a red-white-ish colour. I was wondering whether I could move them, or space them or out or something. They are so tight together. How far appart should they be? do they only have like 3 sets of leaves? I have one in a pot which I bought about 3 days ago, what compost? Feeding? There is no tab in the pot that says this.