Inexpensive software is available online for PC and Mac computers. A popular choice is Audacity. It’s capable of professional level production but it’s free. I use Adobe Audition and currently have an education account, which gets me 50% off the monthly subscription (I pay around $30 rather than $60). If you are a student or teacher, or work at a non-profit, you might qualify for education pricing. All Adobe products are also available as trial software (30 days).
Recommended Software: Editing Audio with Audacity and Audition
Audacity is free and highly rated audio editing software. Audition is part of the paid Adobe Creative Cloud software suite.
Note also that although I don’t recommend diving into video editing software, it can be used to for some simple multi-track editing of video AND audio files. If you had iMovie or Adobe Premiere for example you could do some basic trimming and arrangement of your audio files.