Connect a domain and change the website with Squarespace

Hi, 

I've just finished building my page with Squarespace and before I connect it to the domain I own, I want to know if I'll be able to make any changes to my website after I connect it with my domain or, after I do so, I won't be able to change anything.

Thanks.

Its your site, and you can edit  it anytime you wish. Certain major things can't be changed like the domain itself or changing to a different template. 

Do you mean editing your old site after you connect the domain?

If so and it is on Squarespace - yes, you would just log into that site.

If it's on another platform like Wix or WordPress you would just need to make sure that you have the login details and the url to login - especially for WordPress: https://www.wpbeginner.com/wp-tutorials/how-to-change-your-wordpress-site-urls-step-by-step/#:~:text=This method is the easiest,and 'Site Address' options.