What should I do to prepare

[Texas Aggie]

Don't worry about any supposed bad habits, though I know what you mean. For one thing, its been a while, and for another, my reference was only toward an understanding of a) the positions on the field, and b) the BASIC responsibilities of the position (i.e., line judge tends to cover downfield more than linesman and is responsible for downfield in a 4 man crew).

The actual mechanics may not be exactly that, but from what I've read and seen, that's sort of the idea.