You already get static a static IP address.

Ping requests are dropped by DigitalOcean firewall by default change your firewall configuration to allow incoming ping requests to be able to ping.

Disabling ping requests is a security mesure for preventing attacks like ping flood.
You can try to SSH into your server by:

$ ssh root@your_droplet_ip_address

Traffic on SSH port(port 22) is allowed by default by D.O. firewall to allow remote access.