You will get full administrative control of your VPS, therefore you can surely open/close any ports on your VPS.
Windows VPS:
If you have Windows VPS, you can refer to our following article to open any specific port.
https://manage.accuwebhosting.com/knowledgebase/2214/How-to-Open-Ports-in-Firewall-on-Windows-Server-2008-R2.html
Linux VPS:
If you are using Linux VPS, there should not be any default firewall preinstalled. In case if you have installed any firewall on your VPS please refer to your installed firewall manual for more details.
