Colouring my bleached hair with softer ash(like champange blonde)

Remember when you do the regrowth it won't look the same. It sounds like you will generally need to bleach and tone

You should wait four weeks between processes such as bleaching and permanent colours (including permanent toners, ideally).

It's hard to give any advice when we don't know what your hair is currently like and what sort of shade you're trying to achieve.  I know you said champagne or ash blonde, but to be honest, in my head champagne blonde is very different to ash blonde, as champagne has more golden tones and ash more cool tones.

Are you looking for something more like this:

or this:

And any description of your current colour would be helpful, too, whether you're banana yellow or custard yellow or lemon yellow ...