Some great answers have been given here!
Assuming you have already paid off all debt.
First thing I would do is buy John Bogle’s “Little Book of Common Sense Investing”.
https://www.amazon.com/Little-Book-Common-Sense-Investing/dp/1119404509/ref=redir_mobile_desktop
I would then heed Mr. Bogle’s advice and invest in Vanguard Index funds and avoid any financial intermediaries. Investing is easy. It just requires discipline.
Depending on what your objectives are you might invest a portion of the money in the Vanguard High Yield Corporate Fund, particularly if you need interest income to live off of.
In the long run stocks are the safest investment because they outpace inflation. If you are a buy and hold investor and can tolerate severe market swings with potential for greater than 50% declines without panicking, like we experienced with the dot com bubble and Great Recession, you will be rewarded.
Of course you will want to take advantage of any 401(k) matches you might get at work, and also maximize your Roth contributions since that’s the best deal you will ever get from the government.
The most important thing is to keep your investing costs low! That’s why Vanguard is the best. They aren’t publicly traded or privately owned. Due to this unique structure they don’t need to generate profits to distribute to others. Vanguard is owned by the shareholders themselves and therefore operate at cost. Every basis point in expenses you can save adds to your return. Rely on the power of low costs, simplicity, and tax efficiency. Those are fundamental principles that work to your advantage year after year.
Look up “Compound interest calculator” and run a few numbers yourself to see what a huge difference saving expenses makes over time. You won’t belive it until you see it for yourself. That’s why financial advisors are to be avoided. Bogle refers to them as “the gradual transfer of wealth from the investor to the financial intermediary”. He’s right. Read his book. Everything is there.