what are good ways to improve your singing at home with no vocal lesson or training?

first off, i can not afford for vocal lesson or training for now,
so i am looking for a good ways and tips and exercise to improve my singing or vocal .
how can i improve my singing and vocal ability at home without getting a vocal lessons?

Record yourself singing. Listen. Make a change. Repeat.

Though it’s best to use a speaker and mic, so you can hear yourself in real time.