SEO Expert / WIX to Google Domain Upload

I have an already designed website for my son's new business but it needs some extra TLC with the SEO info, help with how to use the WIX Google advertising voucher that came with the WIX subscription, for the site to be uploaded to the Google domain and anything else the business needs to be more visible in search engines. I am too busy with my own work to do this so thought the best option would be to hire a specialist. This is a very easy and fast job for someone who knows what they are doing.