US ETF Recommendations

If you're looking to keep in really simple I'd look to an S&P 500 or total market ETF yes. Historically, the S&P 500 has outperformed a US total market ETF which would include small and mid cap companies however this is never guaranteed in the future so what you'd like to choose is completely up to you.
I also imagine you want to be dealing with US domiciled ETFs so I won't mention any CAD listed ones.
Something like SPY for the S&P 500 or ITOT for total market. ITOT's fees are so low it's practically free. You'll pay only 30 cents per $1000 invested annually.
I've attached an image here to highlight the differences in these two funds over the last decade. Again, SPY has outperformed, primarily in a post-pandemic environment because of big tech returning so much. However, it's never guaranteed in the future.