Audacity is a perfect tool for ITC. If you use it consequently like I am doing since years for ITC you don't want to miss it anymore. To get Audacity you first need to download it here. After installation you can make some basic setups I will show you now and that are optimized for ITC. I configured Audacity mainly along with its usage, thus everything I found out as best practice is empirically found.

First go to Edit->Preferences:

Another menu with lots of tabs is showing up. Here we can make all the basic settings we want to use in order to facilitate our work. I just will talk about the tabs that are useful for us. Leave the rest of them in default settings.

The first tab contains settings for the input/output devices. Since all my ITC devices are using the line input of my soundcard it is favorable to specify it for the recording device. In my eyes it makes sense to set mono recordings as default. Stereo tracks don't make sense in ITC. The rest can stay as it is.

Next interesting tab is the recording tab. I valued it as useful to put a default track name "ITC Track" in the Custom Track Name field and enable the naming extension by time and date.

Quality settings are important. Sometimes we need to do a lot post processing. Therefor it is favorable to set the sample rate up to 95KHz instead 48KHz and 32 bit Float to preserve enough reserve in accuracy. For the same reasons i selected the highest quality settings for the Sample Rate Converter as shown.

For copyright reasons Audacity comes without an MP3 encoder. We will do all our exports in MP3 since we want to save disk space and bandwith. Installing an MP3 encoder is not much of a problem because you can usethe famous Lame encoder. It's free and you can get it  here. After installation it should be visible in the Libraries tab. If not use the buttons for FFmpeg Library to show Audacity the installation paths.

The Effects are not important for the start but later we will use the Nyquist extensions. Thus it makes sense to check the respective box already.

Now restart Audacity. In the lower left corner you should see now the new Project sample rate of 96.000 Hz. For the audio position check hours, minute, seconds and milliseconds and for the selected areas "Start and Length of selection". This is useful if me measure duration and spacing later.

In the upper left corner you should see now Line input as default.

Now you are done. Audacity is now ready for ITC.