Each effect in Audacity comes with a predefined set of values that you can change and save according to suit your needs and workflow.
When you select an effect to apply to your audio (for example Effect > Noise Removal & Repair > Noise Gate...) Audacity will show you the effect settings window where you can change the different values according to your needs.
After you find the settings that best suit your needs you can use the Presets & settings button to save your settings for future use:
Click the Presets & settings button and select Save preset...
After saving your presets you can recall them the next time you need to apply the same effect. Click the Presets & settings button, select User Presets... and select the name of the previously save presets:
To restore the factory default settings select Presets & settings > Factory Presets > Defaults
