Any business is useless without customers!
Before you get too involved with all the other stuff, get out there and find out for yourself whether you have what it takes to build a round. Many, many would be window cleaners buy themselves a full whistles and bells set-up, only to find that all that fancy equipment means nothing to Joe Public - they are not going to be queueing up to beg for your services!
Knock on doors and then more doors, and then more doors. Start compiling a list of customers, it doesn't matter if you're not going to be ready to clean for a couple of weeks, tell them that and they'll wait.
Once you know you can grow a worthwhile business you'll still have plenty of spare time for all the other things - you're not going to be run off your feet for a few months yet!!
Best of Luck,
Ian