Assuming your on windows you can go to tools - edit wallet config and add this from the masternode setup guide.

http://crowdcoin.site/guides/Windows_hot_wallet_Sentinel_Guide.pdf

Or just copy and paste this:

addnode=80.209.235.89:12875
addnode=212.24.104.67:12875
addnode=195.181.245.127:12875
addnode=109.235.65.47:12875
addnode=136.243.89.142:12875
addnode=13.58.35.83:12875
addnode=86.57.164.146:12875
addnode=35.185.4.126:12875

Let me know if you still need a little help.

Thanks

DubProdigy