I just opened my first node today using a static ip (Vultr). Do i need to keep the desktop wallet open?
If you have your masternode running on a remote vultr server then your personal computer can just turn off whenever. Only your server needs to keep running. So you're good!

There's a masternode support channel in the official discord group at
https://discordapp.com/invite/NabdcJ7 which has other useful info.
Cheers!