I'm trying to understand stocks. My current view is the following.
Assume I have a company and I need money to expand my business. Instead of taking a loan I give people the opportunity to buy a fraction of my company. When buying a fraction one gets voting power in proportion to the amount of shares one owns (I know this could vary but let's keep it simple and focus on the gist of it) and certificate (maybe inaccurate word choice) that says "you own X amount of this company" and this certificate has some value that is determined by the current supply and demand (except in the initial release of shares).
Now, I was the one who decided how many shares were declared and to what price they were initially sold at. Let's assume all shares were successfully sold, now the shareholders are free to sell the shares at lower or higher price and then the market will continue on its own. Here comes my trouble to understand and my question. The company only received money from the initial selling of shares and will never receive money from the shares again? Also the value of the shares is completely independent from the amount of money the company has and how the company performs? I know that a prosperous company correlates with increased value of share but it does not necessarily need to increase also the other way around does not need to decease when a company loses money. It is as the company and stock are two completely different identities with some vague connection which is the "certificate".
In short, does a company only profit from becoming a stock in the initial release of shares?
P.S. I'm not looking for some vague answer that a company can profit by the majority of shareholders voting and running the company which in turn produces revenue.