The default samples library is full of surprises. You will have a lot of fun exploring it but at some point, you might want to download new audio samples. You'll find tons of websites selling audio samples for music production, ranging from the less expensive to the most priciest thing you've ever seen. However, there are good ways to find free and high-quality audio samples for Tidal.
Here is a small list of websites for free samples you could check:
Freesound: Free ... sounds.
BBC Sound Effects: Direct from the BBC. Read the license!!
Legowelt Samples: free samples from Legowelt by Legowelt himself.
Music Radar: a huge amount of free audio samples. Ranging from very good/high quality to meh-quality.
Reverb Drum Collection: Reverb Drum machines collection.
We Sound Effects: a fairly large collection. Read the license.
Young Guru Breaks : breakbeats handpicked by Young Guru.
Sounds from Space: sounds from space... For composing
VSCO Orchestra: Yes, live-coding the orchestra. It works, sounds like Boulez.
Free samples for all: a Reddit community.
99 Sounds : More than 99 samples.