Use your cash to pay off your auto and student loan debts.
Maybe sell the car if biking is an option.
What is the mortgage rate?
Keep some cash set aside as an emergency fund.
With what's remaining open a Vanguard account and buy a low cost total market index fund (e.g. VTSAX). Add to your holdings regularly and consistently, every paycheck. Don't worry about ups and downs, it's all noise and the worst thing you can do is panic and sell while the market is down (sounds obvious, but so many people make this mistake).