Actually, I just do basketball. I know a lot of guys that do multiple sports. Football/basketball is usually the whistle. Baseball/basketball is usually giving the hammer on fouls instead of the straight arm.
The reason I asked if you were the R, was that would make you more comfortable reporting fouls.
Basically from a mechanics stand point you will be about where all first year officials are.
You should have an edge in being comfortable making judgments and understanding how the rule book works.
I'll give you the same advice I give all new basketball officials.
Have a strong whistle and voice. Give a good blast and vocalize what you have.
Practice signals and foul reporting at home in the mirror.
Work as many games as you can get.
Watch experienced officials work and ask questions.
Find an experienced official in your area, perhaps someone that does football too, that will watch you work.
Good luck, and if I can help, just let me know.