1. Live on a budget. You'll benefit greatly by spending your money on paper, before you actually spend it. Plus you'll get to see where you're money is going every month.
2. Pay off all your debts. Get a copy of your credit report and pay off one at a time, starting with the smallest, working up to the largest.
3. Now that you no longer have any debt, with the exception of your mortgage if you're a homeowner, you need to build a 6 month emergency fund. That's 6 months worth of monthly expenses, not 6 months of net income.
4. Nooooow, it's time to invest, and the folks in the FIRE movement (Google it if you need some insight) do their investment lean and mean. They invest with Vanguard. https://investor.vanguard.com/corporate-portal/.
And they invest 15% or more, (trust me, if you can put more in, do it.) into the VTSAX fund. It's the Vanguard Total Stock Market Index Fund. It gives you broad exposure to the entire market. The fees are 0.04%. That's INCREDIBLY low. The minimum investment to open an account is $3,000. I just opened my account today, in fact. And remember, give 15% into your investment monthly, follow your budget, stay out of debt and WIN WIN WIN with your finances!