Hello,
I recently received an orchid as a present and the flowers are done but I noticed juice at all the knuckles. Is this anything to worry about? Thank you
Nope. That is sometimes referred-to as "honey dew", and is often a sign that the plant is doing well.
The only potential issue is if it attracts insects, and that's pretty unlikely in a home environment. If it does, a gentle wipe with a paper towel wet with warmed water removes it.