If you want to hire an SEO specialist, you need to have a clear idea of what you want them to do for you. You may want them to do everything or only the tasks you can't do yourself. A good SEO expect will assess what needs to be done and give you a list, such as link building, site speed optimization and fixing broken links. You can decide if you can handle any of this yourself or you want them to do everything. Be sure you're talking to an SEO expert, not a company salesperson, so you can ask them to prioritize the tasks.
One task you should always turn over to an SEO specialist is keyword research. They will have software to do this quickly and accurately. If you have a large site, let them find broken links since they have software for this as well.
If your site does not load quickly, it's usually best to have a professional take care of this unless you're a techie. Likewise, if your site isn't responsive and render well on all devices and screen sizes, have a professional make your site responsive. Face it, if you knew how to do it yourself, you would have done a long time ago.
One thing you may want to do yourself is write your website's content. Get keywords from your SEO professional and incorporate them naturally into the content. Always write about how your product or service will benefit the reader. Too many business owners write about how great their company is, but no one cares. Save self-serving content for your About Us page and make everything else about the visitor.
Be realistic about your free time. The main reason business owners hire SEO specialists is because they don't have time to do the work themselves. SEO is time consuming, even for SEO professionals who use automated software. For more information click here https://www.reddit.com/r/SEO/comments/et9rxm/whatarethemaintasksforanseospecialist/.