The Audacity program is one free and open source tool, with which you can edit audio file, such as mp3.
The Photos app in Windows 10 can split and merge videos. But the corresponding audio application, Groove, is anything but simple player, without any audio file editing features. On the subject of sound editing, you can install a reliably good program, Audacity.
Although there are several audio editing programs, some of which are in the professional tool environment, we find it quite complex and awkward to do most of the common work on editing a mp3 file.
Audacity, on the contrary, is an easy, free, open source application that can do your job quickly and efficiently. Just open Audacity and drag the mp3 file you want to edit onto it. In addition to mp3, it accepts WAV, AIFF, AU, FLAC, AC3, M4A / M4R (AAC), and WMA files.
Your file is represented in a single wavelength format. With Audacity you can cut an audio file into comeyea, you can join two mp3 files or two tracks of files, insert various sounds, record via microphone, use various effects like LADSPA, LV2, VST, and many more.
In the program you can add various plugins, which you can find in its official website. By default Audacity does not overwrite the original file after editing it. Creates one project, for later processing and whenever you're ready, you can export it to one of MP3, WAV, AIFF, AU, FLAC, AC3, M4A/M4R (AAC) and WMA formats.
Audacity is multi-platform, meaning it supports Windows, Mac OS X and GNU / Linux. Today it's in the 2.3.0 version and you can download from here.