Login in your cPanel, in the right side column where all your account information is listed you will see also the Cpu Usage, Memory Usage and Entry Processes information.
You will also see an icon in your Statistics section at cPanel, called "Resource Usage Overview", click on it and you will see all the resource usage history of your account, there you can check if you are hitting the limits and if is time to move to another hosting level to have more resources.
If you have reached any limit, once you access the "Resource Usage Overview" section you will see a text alerting you about the resources used.
