Its always difficult to advise someone what to do.
Personally, I would get some basic equipment and start practicing on your house, your parents house, any house that you gain technique experience and look professional - you know the basics, feel comfortable and can get on doing a new clean looking as though you have been doing this for years. A newbie windie stands out a mile.
It's always better to canvass when its not dark IMHO. The reason is you probably won't be able to see the job clearly in the dark so will be difficult to quote. (I got caught with a pub so I got the tee shirt. It was dark, but was brightly lit up. The windows looked easy to clean. In the daylight the frames were old flaking paint - not a job I would have taken on. Thankfully the pub went bust.
) Potential customers will also be more cautious of strangers when its dark as they don't know who you are, so you will be less successful.
I would also try to get to know a couple of the local cleaners so you have an idea of pricing. Just introduce yourself and explain you don't want to undercut anyone's pricing. Ask them if they know of any areas that have lost a window cleaner. (This worked for us, its called networking.)
There are some who have a successful internet presence, others seem to do reasonably well with leaflet drops but I'm of the belief that the best method to get the ball rolling is to door knock.
Choose an area and start in one corner and knock. If there is no one in, record that and go back until you find someone. If someone says they already have a window cleaner, then thank them for their time. Ask them as an after thought if they know what their windies name is. When you are on the street make a note of that name. Whilst your priority is to look for customers now, you also need to play the long game. (If his name is John and you hear he has given up window cleaning in a year or 2's time, you have a new potential customer list to knock even if he sold the business to someone else.) Build up a house to house record of the area you canvass.
Obviously if you are getting no success in that area, then move to another, but don't forget the first area.
If they have a no canvassing notice on the door then respect that - just post a leaflet through the door. Some ignore it and knock. When the door is answered they apologise and tell the home owner they only saw the notice after they knocked and felt it rude to walk away. To me that's dishonest and doesn't add any confidence when you ask them if they would like the servcies of an honest, reliable window cleaning service.
Once you get a customer and they agree to a clean, then do it there and then if you can. If not, agree a time. Get name and mobile number and check if they have access issues - ie. locked side gates, etc.
Once you have done a clean and got a customer, then you can door knock with a slightly different approach. You introduce yourself and explain that you are wanting to expand your window cleaning round into this area. Once your customers are happy with your service, then ask them for a referral. Are any of their friends locally interested in a good, honest, reliable window cleaning service? Don't offer incentives for names. ( A large % of our customer base has come from referrals and recommendations. We have one customer who got us around 20 new customers over the years including a business clean.) Once you do a clean, then knock a few doors around. We've just cleaned the windows for Mrs Gibson next door and wondered if you would be interested in
our service as well. (Our is better than my.)
Forget about small talk for the next few years. Your new focus is window cleaning. If you see someone cleaning their own windows, stop the van and ask if they need someone to clean their windows for them. They can only tell you to get lost.
Once you have a customer the best way of collecting is via go cardless or some other process where you take payment a few days after the clean automatically - but only when you have done the clean. We have started to push BACS but customers forget to pay or pay you when they decide to. A lot of our older customers still pay cash and we do still collect on a Friday evening. Its a pain but a good way to start off as you can spend a little time with each building their confidence in you.