first of all, you know the purpose of the bike? You know the sizing you need? How tall are you, whats your inseam? Are you going to cycle only to London Fields in the summer time, or use the bike all year round for commuting purposes? wanna gears? wanna brakes? instead of "dunno", write down what you have in mind. which bikes look nice in your opinion, so that they can be adjusted to fit your purpose.
Thanks, just updated the intro.