Welcome!! We are here to help were we can... don't be afraid to use the community for advice/help. Make sure you build a proper mesh from the beginning.
https://docs.hubitat.com/index.php?title=How_to_Build_a_Solid_Zigbee_Mesh
https://docs.hubitat.com/index.php?title=How_to_Build_a_Solid_Z-Wave_Mesh
In addition especially for the C-7 starting with repeaters placed judiciously around BEFORE including other devices seems to be a very good strategy for success.. the two that have worked really well so far are the Aeotec Range Extender 7 and the Ring Alarm Range Extender (yes you can use it for HE).
https://www.amazon.com/Aeotec-Extender-SmartStart-Compatible-SmartThings/dp/B081G97TLB/
https://www.amazon.com/Ring-Alarm-Range-Extender/dp/B07ZB2VP4K/
Also maybe recommend getting a Z-Stick in case you need to do some impromptu ghost removal or just to exclude stuff. The advantages of the hubitat system is everything is local but that also means it can't hide any issues behind cloud processing etc.
It may seem overwhelming at first but there is a lot of potential and possibility, start with the more simple rule apps before diving into RM.
