The best thing I can suggest is to make some solid connections. Build up a list of people you can collaborate with on both the supply and demand sides of your business.
Find a business mentor who has experience in the field you're entering and who you feel comfortable with. Let them guide you.
Work out all of your expenses, from product to paperclips, add on a realistic amount that you need to live on. From this you can work out how much turnover you'll need to achieve that, taking into account any taxes you need to pay. This will tell you if your business is viable.
Think very carefully about your minimum viable product (MVP). Launch when you have that. Don't worry about features but it has to work perfectly. Features can be added later and you may decide to change what features you offer after initial feedback from your customers.
I often have tips and advice from my own business experience on the 24 Beers blog. You can read it at www.24beers.co.uk/blog/
