A well-run Google Business Profile can win map pack calls on its own in a quiet market, and you can manage it yourself for free. In most Melbourne markets it is not enough, because a profile cannot rank in the organic results or build pages for each service and suburb you want work from.
Start with the profile either way: verify it, choose the right primary category, list your services and service areas, add real photos and ask every happy customer for a review. Our local SEO page covers what moves the map pack.
Add a website and SEO when competitors with strong sites keep appearing above you, or when you want work from suburbs beyond your address. Google uses your website to judge your profile too.
This is one part of a bigger picture. How to choose an SEO agency in Melbourne covers costs, contracts, what good SEO includes and how to spot a bad agency in one place.