I have always found that in SimCity games (note: I haven't played on iOS, but your question implies this holds in that version) if you try to front-load the city to be immediately awesome (ie, build all the services up front) you will quickly descend in to unavoidable bankruptcy.
This is because the best occupants to each zone generally won't appear without good ones from other zones - well educated sims won't move in without good jobs being available and better businesses won't appear without well educated sims to come work for them, etc - everything that gets build at the start will be "low quality" and won't earn enough tax to sustain a full set of services.
If you follow the (over-simplified) rule of not building any service that has an upkeep unless you have sufficient budget surplus to cover that upkeep, you should avoid the most serious of financial problems. Exceptions can be applied if the situation is urgent, such as power or water shortages, and for the first few vital services, such as a fire station to avoid early disasters.
Yes, this means your city will start off a bit crappy, with uneducated, unhealthy, unhappy sims - but when has a fully formed city ever been founded from nothing? Over time, as you improve the city, your earnings from tax will rise (as more affluent and higher density businesses, residents, etc eventually move in) forming a positive feedback loop that allows you to improve the city further, and so on.
So, step one is drop some residential zone and get those first people jobs. Improve their lives a little bit once they are paying tax, then expand and repeat. It will take time and effort, but the big sprawling high-rise city full of awesome will eventually come to you.
