Ever a bad time to buy spy(now)?

I'm a beginner so simple explanations are preferred 🙂

I understand that spy is index/average of the 500 largesr companies in the U.S and is a recommended beginner friendly investment that you can “set and forget”

Is there ever a bad time to buy spy – say given today as an example? Even today where I get the sense that it's a bearish market, you would get a good price