how to get my WP site’s IP? [closed]

This is more a general hosting question, rather than WordPress.

Nonetheless, since you mentioned that you have your website on WordPress.com, you can have your new domain point to your WordPress site by it’s CNAME. In your case, your CNAME would look be example.wordpress.com (change example to your actual site).

This is the recommended approach since using a CNAME rather than the A record because if WordPress.com changes your IP, the CNAME will alway point to the right one.

Otherwise, check out this article that WordPress provides to point your custom domain: Use a Domain You Already Own (Domain Mapping)