I very often say to my adult students that they shouldn’t try to sound ‘Spanish’, but should simply aim to get the pronunciation right & speak in their own ‘voice’. One day they might start sounding more Spanish when they speak Spanish – children of other nationalities who grow up here & attend Spanish schools certainly will – but it doesn’t really matter if they don’t.
Also, Spanish is spoken in so many countries that accents are vastly different across the world, & even just in Spain itself.
Here are some videos.
This is how they speak in Andalucía – andalú