IRA mutual fund suggestions?

I am a small business owner and have a traditional IRA (traditional (for now) due to my accountants suggestion). I'm looking for some solid mutual funds to invest in. All I currently have is VOO and the individual stock in Estee Launder (EL). I'm wanting to be well diversified.

I'm young and have plenty of time to let it sit. I love looking in to this stuff- What do you have for me?!