This is too vague to give an in depth answer as we don’t know your ultimate goals or your diet as a whole but not eating before working out isnt bad. Some diets such as intermittent fasting involves fasted work outs.

Changing both your diet and work out habits can be hard, especially if you do it all at once which can become demoralising and hard to maintain over the long term.

I encourage you to research different approaches towards your ultimate goal and make smaller changes over time with a view of changing your outlook on food and exercise for the long term and making it stick.