Single Use or Multi Use?

Hi there!:blush:

I’m about to buy a short audio clip and use it in my introduction for my vlog videos. Does this mean that I have to buy “Multi Use” since I’m going to use the sound several times for different videos?

Also, how do I credit or prove that I have paid the the artist/creator for their sound or music in my videos?

Thank you very much for your help! Would appreciate it!