First of course is to slash unneeded expenses, especially recurring monthly expenses such as TV, phone, subscriptions, memberships, utilities, etc. And especially cars. You may have already done that. Then max out emloyer retirement plans unless they are really bad. Low cost stock index funds are best where available, such as S&P500 funds.
Next open a Vanguard IRA and start dumping money into stock index mutual funds, half USA and half international by default but you need to research and see what is right for you. VTSAX is a good starting point. Others like Schwab and Fidelity are also good, with their own funds.
Real estate investing may be profitable in your area as well, especially for non-tax sheltered money, if you want to be landlords.