Ahh bookkeeping.
There are some subtleties here depending on your corporate form and where you are located. With a pass-through entity like an LLC, the typical way you do things is to physically transfer money from your personal checking account to the business account and record that as a "member contribution."
This. Is. Not. Income. You will, under almost no conceivable circumstance, either want to or be obligated to recognize it as revenue of the business. It will not be taxed.
In an LLC, moving money from the LLC to your personal accounts is a "member distribution" and works the same way.
You might wonder if a member distribution is income, and the answer is "kinda orthogonal!" In the main, the LLC will be throwing you cash that is actually income, but there are ways (like e.g. running a balance on the business' cards) where the business can be transferring you money in excess of its actual revenue. This is why you have good books; you want to be taxed on revenue, not on cash flow. (Paying income tax on $25k which you borrowed from a bank and have to repay the full amount of would be gratuitously unfun, right.)
In terms of keeping all of this straight, you should use bookkeeping software, a bookkeeping service, or a bookkeeper. I have an opinionated choice here: use Bench (bench.co). They're nothing short of lifechanging for me. I did all my own books for ~8 years and suffered enormously from that; I have had amount of bookkeeping-related suffering decline to virtually 0 after using them. [+]
In the case where you're running a non-passthrough entity, your contribution could get counted as some sort of capital or perhaps a loan to the business. Either way, get it in writing; you'll need it both for substantiation purposes and to make other stakeholders in the business (investors, tax agencies, etc) happy.
Your books will generally be used by your accountant or yourself (assisted by tax preparation software) as an input into your tax filing (and/or tax planning) processes.
[ + ] Literally in the past 24 hours my Bench books caused me to trivially catch an accounting firm from making a $50k error on my Japanese taxes. (Not $50k of net tax impact, but they botched a box by $50k, in a fashion which would have required an expensive remediation next year.)