Active job

Landscaping - Retaining wall and flattening sloped part of lawn

I have a sloped lawn, most area is occupied by deck, I am wanting to flattened the slopy area by building a L shape retaining wall right after deck (2 sides) and digging/filling the remaining area to make it flat. I have not done any measurements, but I am assuming the total area wont be more than 10-15 sqm. I am looking for someone who is qualified/certified and knows council regulations. Please provide a free and cost effective quote, if I am happy with the job, there are other work coming in the future for do up property.