Why do you say it is a waste of time? Very rarely is more knowledge a waste. Also which people would you suggest I talk to? Everything I have read has suggested a business plan is essential and this book has been recommended by an awful lot of people. I'll post a link to it so you can see where I am coming from.
https://smile.amazon.co.uk/Essential-Guide-Writing-Business-Plan-ebook/dp/B015T2TQWG/ref=sr_1_3