We've been investing in stocks for close to 25 years now.
Most of our retirement portfolio is stocked based. We aren't day traders. We have a longer term strategy which means less risk and steadier stocks
The first question you need to answer is what is your risk tolerance.
The easiest is to invest in an index fund. Madoff for example. They will pick all of the stocks for you and you buy a collection of the stocks. You can also look at the holdings a pick the ones that do well or just buy what you like.
My key ones are apple, disney, berkshire, google, amazon, shopify, docusign
I don't do bit coin.