As long as the atmosphere is roughly similar, the native biosphere would have very little defense against us. Sure, some of the defenses that local plants and animals developed against each other might cause issues, or they might not.

We would be an invasive species on the grandest scale. A completely foreign biology would maybe have useful nutrients, or maybe not. That would be the key, but the periodic table will be the same everywhere, and chemistry being what it is, we’d probably see similar molecules, at least the simple stuff. Basic hydrocarbons and such.

The complex biochemistry would be vastly different. That could trip up human explorers.