There are many websites and apps with (free) exercises to learn how to enjoy the moment. Have a look at:

VGZ Mindfulness app (free)
Google Play Store • Apple Store

The mindfulness app
Google Play Store • Apple Store

The website of Mindfulcentrum
www.mindfulcentrum.nl/gratis_mindfulness_oefeningen/
And why not attend a mindfulness course? It might even be covered by your health insurer. Have a look at your health insurer’s website or check with your GP.