No actually I haven't seen that guide before. I just scanned through it a little bit it seems to have some good advice but I don't know about that part that says "if you don't know PHP, and C++ don't worry you can pick it up as you go". lol Not in 3 days. PHP is fairly easy to learn but C++ is a whole different story.
Iv been playing that Shopping Street game you linked me to that's a cool little game. <img src="smileys/smiley4.gif" border="0" align="middle">
I like your game concept idea. It looks to me like you already started creating it. Just keep writing down all your ideas for the game. It helps me to make some rough sketches, and write my game ideas on the same piece of paper as I go. Once you got it all on paper then you can start to edit your ideas this will make things go much smoother. Try to keep it simple some of the best games come from the simplest ideas.
After you got a rough game on paper then the fun stuff starts the graphics. <img src="smileys/smiley4.gif" border="0" align="middle"> Some people like to hand draw there sprites then scan them to there computer, and some like to create all there sprite on there computer that is up to you. Either way you will need a good image manipulation program like The Gimp, or Paint.NET either will work, and they are both free. Photoshop is also good but expensive. I wouldn't buy it unless you actually made a living with it.
I would suggest that you take breaks from this, and go follow Ashly's Beginner's guide to Construct 2. It will teach you a lot that you will need to know to put it all together.
Also your game idea will require some PHP scripting, and database work. Notpad++ is a nice free text editor. And I like to use WAMP as a development server. Don't forget if you don't know the basics to those languages I mentioned I left you the links earlier. <img src="smileys/smiley1.gif" border="0" align="middle"> Once you got your databases built, and all your PHP scripts written you can use the AJAX object in Construct 2 to implement them as you are building your game. Ghengis wrote a nice tutorial on the basics of that: AJAX Example with Construct 2.
These are just all suggestions on how I would go about creating a game like yours. There not the only way to though. There are a lot of very smart, creative, and helpful people here so if you get stuck just make a good effort to search the forums for an answer, and if you cant find it just ask for help. But a heads up questions about PHP coding are frowned upon here because it is very advanced, and beyond the scope of these forums.
I hope this helps a little. I will be looking forward to playing your game. Good luck with it <img src="smileys/smiley1.gif" border="0" align="middle">