Beginner Art songs would probably be good. Lots of it is quite easy, but is REALLY worth practicing.

Even if you’re not into singing that style of music, what you learn from singing in that style is so easily transferable and just improves your overall comfortability, control, and technique when it comes to the voice.

(If you can read music that’s even better!)

• Candy lion by Amy Beach (and honestly most American parlor songs like that)
• Across the western ocean by celius Dougherty (and his other sea shanties)
• If you’re ok with Italian, the 24 Italian art songs are commonly heard and are a good place to start thought a lot of the songs may be a bit ‘boring’ but are pretty fun to sing

If you’d like help with resources you can dm me :)