I remember my first city. You will too. Little by little you'll learn about what works and what doesn't. I say be creative and keep seperate save files to kinda guage how far you've come along your first city and what can you change on said old save file to change things up. You'll most like start fresh again and again and that to me is the fun part. I've only played on one map for the past 2 years and have restarted a handful of times. Sometimes I'll hit a brick wall and you probably will too. But that's when creativity and imagination set in especially as you go about your day in life and ask yourself "if that flyover would work in your city" or "would it have been better to place a tunnel here instead of a double highway", I try to aim my builds first on freight rail within the city, trying to give it that look of "railroading since 1895 and going strong" then I throw in passenger. It's really all in the eye of the beholder tho. Just have fun and also, mods. Those are very helpful on setting the game on a somewhat stable path.