Existing logo needs some editing... what's the best tool?

@Chuleta626 When you say, "I had a logo created..." who created this for you? Was it a work-for-hire designer who made original art for you? Or did you use an online service of some type? Is there a reason why this source can't give you a black-and-white version? As @Monika Gause notes, you need to be sure you own the copyright to the logo and are able to do anything you want with it first. You should have been given a vector file of the logo so it can be sized and converted for any application and from that file, you can use Adobe Illustrator or Photoshop to do conversions but it all depends on what the logo looks like and what elements are included. You have to have it rendered correctly so it will look good on clothing, labels, and dozens of other everyday logo applications. Oftentimes, a logo has to be prepared specifically based on what you want to do with it and professional logo designers will provide you with all of this information and guidance in the form of a brand style guide. But if you are going to do the work yourself then Illustrator would be my first choice but it has a significant learning curve if you've never used it before.

Which file format did they give you?

Check your contract. In some cases the contract might forbid you from making changes to the artwork.