If you know nothing about investing, picking individual stocks during a very uncertain time is most likely a bad idea. If nothing else, for the psychological reasons: panic is the cause of many losses.
Even for experts picking stocks is hard and often leads to failure (although, if they are worth anything, failure means earning less than hope rather than outright losing usually), for somebody with no previous experience or knowledge it would basically be gambling.
But I don't want to be entirely discouraging. What is your goal here? is it to just exploit a time in which you feel you might make some quick money or are you planning rather to start a pattern of regular saving and investment? The first is most likely a terrible idea, but if done well the latter in the long run is likely to be beneficial.
There are 2 key things:
1) Diversification. Don't hold everything in just one thing, because everybody makes mistakes, even Warren Buffet. And if you make a bad mistake in which you invested 100%, or even 50% of your assets, it will be hard to get back up. Meanwhile, if you have 10, 20, 50 companies, operating in different sectors, you can start playing averages. Sometimes you will be wrong, sometimes you will be very right.
2) Time. When do you need that money? On average, the stock market goes up. But it is a *very* bumpy ride. If you have some savings that you need to use in less than 5 years to buy an house or some such thing, stay clear of stocks. Short term treasuries or Certificate of deposit are your friends there. If you plan to keep your stash growing for 20-30 years until you are old? Then stocks are great. The time period is long enough that the bumps on the way matter little.
Now, the second point is entirely up to your life and priorities, so Ill instead delve on the first.
It might seem daunting to try diversifying across so many companies. And depending on the sums involved, even impossible (looking at you, 2600$ Amazon shares). What to do then? thankfully, there are people who do this job for you. And by that, I mean funds. Usually you invest in a fund, and then the fund takes all the money from people who invested in it, and do all the operations needed with the aid of a good team and a larger capital to play with. Of course, you still need to choose what kind of stuff to invest in: emerging markets, USA, Developed countries, etc. You will still need to do research, but all the real heavy lifting will be done for you.
Now, funds are often expensive and there is evidence that funds, on average, can't meet their goals after fees (that goal is generally to surpass a target called benchmark and it is either a stock index like S&P 500 or some other target). Even with high fees, many funds are still good, especially since you most likely can invest in one through your bank.
Other funds, however, bypass the issue by not trying to beat the benchmark but rather just replicate it. For example, with the S&P500 as benchmark, they just buy the 500 companies of the index (weighted by value). This will never beat the S&P500, but it will match it and requires far less manpower and transactions, meaning much lower fees (talking about more than 10 times less). Since this is a rather passive approach which tries to replicate an index, those are often called passive funds, index funds or similar. I would suggest using those, if you are willing to do some more work personally. There are a few good companies in USA offering those, such as Fidelity and Vanguard.
If you want more flexibility in taking money out, some funds can even be traded on exchanges like stocks, but if you are resident in USA, Vanguard and Fidelity funds will most likely suffice.
Finally, still about diversification, there is temporal diversification. On average, you are best off by putting everything in at the same time. But averages are made of ups and down, and investing at the wrong time could delay results for quite a bit. One of the ways to deal with it is to apply diversification even to that. If you have a large sum to invest, you could spread it over a period of time. Some time you will invest in an high market, sometimes in a low one. But you smoothed out the ride, at the cost of lowering average performance a bit. Regardless, this approach (called dollar cost averaging) is what naturally happens when you invest part of your income as it comes in.
Please note: this post isn't made to tell you what to do, but rather to introduce ideas and concepts. It is a bit more complex than just what I wrote and even to pick a fund you need to be aware of your goal, your own psychology and personality, your risk tolerance and in general you should be able to understand what the fund does and how it does it. There is a bit of research to be done, but I assure you that for those basic things it is well within the reach of the average person. Just use google, maybe look up the entities I mentioned (if you have a 401k you may already be familiar with them), search for online discussions.
edit: part of the point is: today specifically may be a good or a bad day to invest, but if you keep at it regularly and well diversified, it is never a bad moment to start. Most likely beats cash on decent time frame anyway.