Q. Can I know what did Lord Buddha preach about worshiping gods?

A / R. Just forget about worshiping gods, even Śakra, Lord of the Devas worshiped (worships) householders who making merit, etc. 

For/To gods, [having done (a) merit (mindly/bodily/verbally)] Transferring merit is all what you need to do.

… “I worship as well, O Matali,
Those householders making merit,
The lay followers possessed of virtue
Who righteously maintain a wife.” …