Black base of leaves cymbidium orchid please help 🙏

[Rosita-Ana]

Hello
I'm new here, I absolutely love orchids but my knowledge is small, I'm learning as I go but so far the orchids I have are blooming.
But a new orchid has just joined the family, I bought a cymbidium orchid off market place which should of been lovely but once home I have seen it isn't well at all.
It has mealy bugs which I plan to use rubbing alcohol to wipe off then rinse.
But worryingly the base to the leaves are very black, I have searched online and can't find what it could be and if and how to help nurse it back to health.
I would love some help please, and sorry if the description is off, I am no expert but have added a photo to help.
Thank you