I learned some really hard (and costly) lessons back in 2013 playing options. I was up huge and lost a ton. Left the entire market for years. Now, I just go long stocks I like and hold. This strategy feels better to me.
The only reason I was looking at covered calls is because it feels like a limit sell order that may not execute but I get some money out anyway.
As others have pointed out: understand before you dabble. (thanks
@winfield100 )
Many posters here were in shares years ago, which were multiplied by 5 due to the stock split and those shares gained in value enormously.
Given the question "how much $ is enough $?" many here started dabbling in options with a part of their (by then) large TSLA holdings. Originally some wanted to play "The Wheel", which means selling covered calls against TSLA shares to convert those into $$. Then, with the money you sell puts until you are assigned shares again. And hopefully you end up with shares and some extra cash. (Not less shares, which can also happen).
The Wheel wasn't very popular though, because of a plethora of reasons. Some had to pay tax every time their calls were exercised by the buyers. Some didn't find the risk/reward profile appealing enough.
Because of this, people branched out into many forms of option selling. The most popular ones right now are BPS (for when you think the stock can't go below a certain price level) or covered calls (and for the daredevils BCS) (for when you think the stock can't go above a certain price level).
What all these strategies have in common though is that they can go wrong, in which case you need to truly understand what you sold/bought and how to turn the situation into a more favourible one. Why I told the story of the current thread is to make you see that many here only risk (small) parts of their portfolios with option plays. (At least at the beginning. Some members were so succesful and comfortable with options trading that they eventually (after months of practice/training) switched their entire portfolios to cash, but know that this is the exception to the rule. I believe most here hold TSLA shares also.)
By your first question ("how many shares do you need for one CC?") it is clear you don't have enough knowledge to jump in the fray without further preparation. I don't mean offence, of course. Anything can sound rude on the internet, but I mean the opposite. I'd like your future experiences with options to be positive ones.
I suggest you do some more research (for example by watching some videos on covered calls, the most basic of strategies) and in the meantime save up to buy some TSLA shares to get you to that nice round 100 number. After that, you can start selling one covered call at a time, preferably on days where the stock has rallied and easily another 20% out of the money with an expiration date not too far off (one-two weeks IMO).
This should net you some "gravy", i.e. quite risk-free cash income to your portfolio. Once you will have reached this point, your knowledge will have grown greatly and you can start tuning your option trades according to your risk-reward profile, personal goals and time horizon.
TL;DR: stay safe out there and good luck.