Soft cane dendrobium - advice for a beginner?

[bunny]

Hi, I'm new and looking for advice on how to care for a soft cane dendrobium. I've been googling but have been finding contradicting advice about when to change watering patterns, seems to be consistent when described by growth phase but not when described by month or season. I don't know what phase mine is currently in.

I got it in early January (from a supermarket), it was in bloom and had some flower buds. Everything has gone well so far, the buds bloomed and the flowers lasted a long time, the last one fell off a day ago. It has 2 canes (blooms were only on 1), each cane has one keiki. I keep it indoors next to a window with indirect sunlight, my home is usually between 20C and 24C. I don't know humidity level but I try to keep my home on the more humid side.

I've been watering about every 10 days. I think I missed one watering and one cane (the one that had flowered) began to shrivel, I watered it (the flowers fell off within 2 days afterwards) and it is now much less shrivelled.

I would greatly appreciate any advice on how to care for it, especially regarding different growth phases (and suggestion of what phase mine is in).
How important is fertiliser? I don't have any currently.
I have read that if leaves fall to leave them and not remove them from the pot, is this important as fertiliser? does this apply to flowers as well?
Please correct me if I'm doing anything obviously incorrect!

Thank you in advance!