Put your cooled wort in primary fermenter (bucket or carboy). Add yeast, then add lid+airlock if you have them, otherwise non air-tight sanitized cover works too. Wait three weeks and you might be ready to bottle then.
Or put wort in primary fermenter, add yeast, then transfer to secondary after 1 week.
Do not transfer your fermenting wort after only 1 or 2 days in primary. It isn't ready yet