Its very common problem, do following steps.
1st) check your domain nameservers are correctly updated in domain name registrar end as well as confirm you are updating correct nameserves for your domain.
2nd) If every thing correct then try to ping your domain from two networks from command line.
If you receive time out from both server then try to ping server ip
ping server ip address
once you able to ping server ip contact your hosting provider and ask them to check DNS configuration for your domain.
3) If you are able to ping domain from one network but getting time out from your own network then browse following url and ask your hosting provider to check your local machine ip in server firewall and remove it from firewall blocklist if its block in server firewall.
What Is My IP Address - Shows Your IP Address
4) If every thing is correct like you are able to ping domain and domain resolving from your server and still you are not able to access cPanel then simply disable your local machine antivirus/firewall as some time local machine firewall/antivirus blocking cPanel ports (2082\2083).
If above all steps not working for you then contact your hosting provider and ask them to enable proxy cPanel for your domain, so that you can browse cPanel by using following URL because proxy cPanel working on port 80.
Hope it will help you.