what soft wood can i choose for my breeding budgies so they can chew what wood is safe for them to chew

Pine, hard wood, oak anything that is not treated, Like treated pine will poison your birds, I don't know what sort of timber you have over there.

Pine wood is soft the birds chew it in no time. My perches are hard wood. OR Tasmanian Oak.

Nothing with chemicals, stain or paint on it. Even if it has been previously treated it still can not be used.

Osman, You have been advised not to breed numerous times now. Please stop breeding your birds and RESEARCH, RESEARCH, RESEARCH! Research is a major part in breeding, and you should have done it before you started breeding.

 

As already advised, any untreated wood is fine.