You definitely want to show off your education, degrees, certifications, and any other education that would boost your credibility. As a freelancer, these serve as strong signals to potential clients about your credibility. The more strong signals you can send, the more negotiating leverage you have with pricing.
The skills section can help you highlight well…your skills. These might help you show up in search results, so include the ones you have. But don’t worry about over-optimizing these — they’re incremental improvements.
By now, if you put even the smallest amount of effort in, your LinkedIn profile is better than it was before.