any mining pool yet
Energi is no longer PoW.
Is there a set date monthly that the staking is paid out?
Every block, 2.28 NRG goes to a staker. In order to get any staking rewards, you must win a block which results in receiving the full 2.28 NRG reward. So the payouts you will be receiving while staking will not be paid out to you on a regular schedule, but rather sporadically as you win blocks.
You can check out our staking calculator on our block explorer to get an estimate for staking rewards:
https://explorer2.energi.network/#/We also have a staking FAQ here:
https://www.energi.world/faq/#staking