I have been talking with another person in the #add1challenge about Spanish and listened pretty carefully to her day zero video, in which I could hear what she sounded like in Spanish right now.
One thing you can do pretty quickly to improve how you sound is to know where the accents fall for words.
Found this web page with a few rules. The rules are not too complicated. And after learning them and then observing when you listen, you should be able to improve how you speak in this regard quickly.
I started learning Spanish in high school, took it for three years there. That gave me some foundation for Spanish.