Hey @Majid_Nawaz!
I haven’t done a migration myself, but I’ll try to answer the questions I know the answer to and then provide resources for others.
First up, this article covers a lot of the questions - https://www.davydovconsulting.com/post/switching-from-wordpress-to-wix
Pre-migration
I haven’t used WordPress so don’t have an answer - hopefully someone else in the community might be able to contribute.
Content Migration
You can import your blog posts from WordPress to Wix. Here’s an article with more info - Wix Blog: Importing Blog Posts from WordPress to the Wix Blog | Help Center | Wix.com
Most content will need manually moving, such as content on pages themselves (text, images etc). You’ll also need to rebuild the pages as needed.
Wix also has a CMS for item based data that is often used to power repeaters, or dynamic pages. More info here - CMS: Importing Content into a Collection | Help Center | Wix.com
Design and Layout
Wix is drag and drop - you build almost anything you can imagine 
You can find Wix templates here, and Wix Studio templates here.
SEO and Redirects
I’m no SEO expert, but here’s an article with more info about setting up 301 redirects within Wix - Setting Up a 301 Redirect for a Page on Your Site | Help Center | Wix.com
Functionality and Plugins
Wix has a lot of features and the Wix App Market that provides additional functionality that can be added to your site.
It depends on the functionality you need on your site.
Post-Migration Steps
Go ahead and publish the site and play around - from my POV, it’s one of the best ways to know if things are working.
In general, it’s worth noting you’re not going to be able to import your site directly to Wix - you’ll need to rebuild pages, setup redirects etc.
That being said, I’m sure you’ll do a great job and will love it here