Caseylee, they are not hard to grow, they like sun, dislike damp and cold. Don't plant them too early, ideally in well manured soil. They just like to wander if they are the vining types but there are one or two more compact bush types that don't wander so much. Re planting in a pot, the short answer is yes, but don't if you don't have to.They will then needing training up a trellis and they need a big pot, it also depends on the variety of butternut, you will also need to give the fruit some support if you grow them vertically, you can grow in a pot and let them wander over the ground but you are not really gaining anything unless you are short of space and allow the potted plant to cross the lawn. You will have to feed and water often in a pot too. Some of the much smaller squash are better for this, but it can be done.
If you can tell me which variety of butternut you have I can advise you better.
Squash are not always in the gardening books as they are still fairly newish to the UK and there is not too much info in the books usually although I am very pleased to add they are gaining in popularity all the time and fast too, there are a lot of squash growers on A4A.
XX Jeannine