The cost per month to stay at an RV park can vary from park to park and what size your RV is and what hookups your RV requires.
Typically though living at an RV park costs between $30.00 to $50.00 per night but sometimes you can get a monthly discount if you're staying longer in an RV park.
So you might pay between $400.00 to $900.00 per month for a stay at an RV park but some RV parks may charge as much as $1,000.00 per month which sometimes but not always includes the water, electricity and usually WiFi is included.
RV parks do sometimes let people stay for months and years if they want too and can pay but most people just stay a few nights at an RV park and then move onto a different RV park.
If you're planning on just living full time in your RV it's usually cheaper to just buy your own land and live in the RV on your own bought and owned land instead of living full time in an RV park with constant monthly rent.