Long Term Investing stocks

For Long term investing should i just invest in a S&P 500 etf? Something like IVV since i have a fidelity account? Or is something like a mutual fund better? Right now im lightly invested in FTEC and DGRO. Im thinking about picking up AMD or BAC but im not sure yet.

Buying at a all time high doesnt look like a good idea. I wouldnt put my money on a long position in equity any time soon