From the additional info you've given I can tell you this:
It would be much better if you find a third person, an expert, not involved in delivering any of your projects. This person would supervise the work being done for you. It is extremely easy to lie to you and mislead you, simply because you do not know what to look for, nor do you know what a good answer is to a question (and for that matter, you do not even know what question to ask). All the contractor needs to do is give you a complex answer to your question and that will get you off his back for a while. If you ask for a clarification, he can give and even more complex-sounding answer and send you to do homework for another while. It's a game you cannot win in short term, even if you devote all your time to it (shouldn't you use that time to start a business?).
There are many things in technology that are even a matter of personal preference, so if you manage to ask the right questions, you have to be able to discern between a good answer and a BS answer. The field is so complex, that you cannot hope to catch up.
Here are some more reasons you need a third party to be an interim CTO:
You do not know what a system architecture is. You ask the question "How can I get a working knowledge of coding." Do you realize that building computer software for a company is analogous to designing an automobile from scratch? You are here asking how to be a mechanic. What you need done is way above and beyond simple coding.
You cannot judge what a good deliverable looks like. How do you know a project you just got delivered will not blow up after you have 100 users/connections/records? 1000? 10,000? Does the design of your system lend itself to be updated with minimal trouble later? Did you receive complete source code for your delivered project? You do not have the know-how to judge, yet being able to know this is vital for you.
You may have the best business plan in the world, but you have no set vision for the technical aspects of your business. Do you know where your architecture is headed within one year of projected growth? Three years? How will it scale? What will you need to buy? What will you need to rewrite? You have no idea, and the contractors you are hiring don't care.
You have no idea what to do in an emergency. Would you even know where to start if the system had downtime? What if you call one of your contractors and he shifts the blame to another system/component? What if one contractor does not respond in time? What of one does not respond at all?
There are many other things that come to mind. All of these I mention above are things that take years of experience to acquire; you cannot learn this in any one book.
The fact that you are using several contractors makes the problem even worse, since there is no shared vision in what you are doing.
You are at the mercy of your contractors, hopefully you are not giving your projects to the lowest bidder every time because everyone will cut corners and deliver half-done time-bombs that will explode long after you have paid their bill.
Hopefully you will get a CTO-type on board either as a consultant (it cannot be one of your contractors) or as a partner. You should not be trying to learn coding, the problem you have is not even coding-related.
EDIT: This is not all to reflect badly on you, you just don't have the skill set required for this aspect of your project/business, so you need to find it somewhere else, that's all.