John Gill Commentary Deuteronomy 12:30

"take heed to thyself that thou be not ensnared to follow them, after that they are destroyed from before thee; and that thou inquire not after their gods, saying, How do these nations serve their gods? even so will I do likewise." — Deuteronomy 12:30 (ASV)

Take heed to yourself, that you are not snared by following
them
Their examples and customs, and so be drawn into the same idolatrous practices; see (Psalms 106:35Psalms 106:36) , after they are destroyed from before you; for their idolatries and other sins:

and that you do not inquire after their gods ;
what they were, their names, forms, and figures:

saying, how did these nations serve their gods ?
what was the manner of worship they gave them? what rites, customs, and ceremonies did they use in their adoration of them?

even so will I do likewise ;
or however, if this was not determined on when the inquiries were made, there was danger that this would be the result of them, and therefore the caution is given.