Physically removing duckweed from the surface isn't difficult.
The simplest way is to run your hand across the surface, and scoop it up. It's quite satisfying. You don't want to do that when the water is cold.
If the pond too wide to reach across then you can collect duckweed by stroking a bamboo cane over the surface and bringing a pile to within easy reach.
A rake can sometimes work, but doesn't work if you have oxygenating plants just below the surface, because it will entangle with them.
I'm not exactly sure what you mean by 'pond weed'. If you mean blanket weed, which looks like candy floss, then that can be removed physcally by winding it onto a bamboo cane.