While the server are at big load sometimes the subscrision went through but is incorrectly displayed as pending, in that case you can either ignore it or remove it and subscribe again. If the load is even higher sometimes it seems to not go through, but this case is rarer.

Often finding precise information for light values is quite hard, so I use those 3 websites: https://growlightmeter.com/light-requirements-for-plants/ https://plantlightdb.com/?q= https://www.houseplantjournal.com/bright-indirect-light-requirements-by-plant/ (Scroll down)

They don’t always agree but they are a good starting point.