Hyde here from Shopify.
If you're experiencing slow loading times for both the website and your store admin, it seems likely to be either a browser issue or an internet connection issue. Could you please try any or all of the following:
1) Testing both out on a different browser
2) Testing both out on a different device
3) Trying a different internet connection
4) Refreshing your browser cache and cookies.
I hope that helps, let me know how you get on!
All the best, Hyde.