Cool Edit Pro hasn't been a thing since 2003. It's now called Adobe Audition, and it's changed quite a bit from the Cool Edit Pro days. Looks like they've gone to a subscription service now, so you have to pay for it. $15 per month seems silly for such a basic program.
I'd suggest giving Reaper a try...the fully functional demo is free to try and never expires. $60 for a proper license that'll carry you through 2 full versions (2-4 years, I'd say).