How to preprae a garden bed

[chandi_sril]

Hi, our lawn is newly laid, approx 6 weeks now. We are wanting to plant some flowers/ vege etc and wanting to create a garden bed. We are thinking of buying the garden edging and fill it with correct soil/ fertiliser. I have added images of our garden and what we are trying to create. Can someone please advise step by step what we need to do and the soil/ fertiliser products that we should get from Bunnings? Thanks!