Welcome to the Fiverr forums.
Not sure about the LinkedIn part, but you should check their ToS to make sure it’s permitted.
Both are important.
For pricing, set it according to the value you provide and the estimated hours you would work, and also keep any fees you want to cover in mind.
Where and how you share your gig is part of doing business, as you need to market yourself where your prospective buyers are. Have you read this yet? https://www.fiverr.com/support/articles/360011292478
You only have 3 minutes of read-time shown in your forum profile. Check out the Tips For Sellers category (with filters applied → forum.fiverr.com/c/Fiverr-Tips/tips-for-sellers/l/top/all?order=views). You’ll find hundreds of threads offering advice on a variety of things to consider and/or improve. (Note: Not all advice can apply to all gigs or categories. Be sure you check multiple sources as there are some false tips, even among the top threads.)
It takes a lot of work to make it as a freelancer, so be sure to research and plan accordingly.
“If you fail to plan, you are planning to fail.” (Attributed to Benjamin Franklin)