Soundcloud can be a godsend or a mine loaded with bombs.
It is basically a repository like how YouTube is for videos but they host music/audio files.
So no, not all soundcloud music are good to use for YouTube.
You have to use music from users that specifically allow you to use their music for YouTube.
Even then you should be weary as some have entered their music into YouTube's content ID and you may not be able to monetize your videos on YT if that is your intention.
Also note that some music for users may be monetizable currently but because many of them are budding artists, they may want to get signed and the status of their music may eventually change over time.
If my music fits your videos, you are most welcome to use my tracks. Read my terms. I require crediting although my music is free.