The filling for an LLC and corp are almost identical--and simple.
Go to your state corp- commissioner. See if your desired
name is available.......they will charge you a fee to have you file
it but before that is done, you must run a 4 consecutive week
legal notice.
Then you are legal.
My preferred idea for you is--
skip the LLC for now.
create a very elementary partnership document of
1-3 pages stating what each of you are bringing into the
partnership. your tasks.
how you will split the profits.
etc
get your biz license as a partnership. Find a decent place
to do your biz........and i can advise on that as well.
buy $1,000,000 liability insurance. that is similar to what
you get with an LLC psychologically but a partnership takes
no time to create--and no state filing fees.
when you start earning 10k a mo and have lots of equipment
then go do the LLC as you will have more liability and need
different protection.
Luck!