The average (American) adult consumes about 22 teaspoons of added sugar a day. And that’s on top of any naturally occurring sugars consumed through fruit, grains, and milk products. You'll find sugar in a lot of obvious foods (cookies, ice-cream, sugary drinks) but also in foods you would not consider to be sugared (meat, yoghurt, dried fruit, vegetables..)
Switching to a no-sugar lifestyle often carries a learning curve. There’s hidden sugar in most products found on supermarket shelves. So you will have to learn to read labels and to know all the hidden names for 'sugar'. A name ending on -ose is probably sugar.
Most doctors and website will suggest to gradually. I went cold-turkey. That way I only had to adjust 2 days. I felt that eating no sugar (I also went no-carb) was the perfect solution for me. I immediately could feel the results. No cravings and no hunger. It was clear for me: sugar is a poison. And even more: sugar is a drug.
If you find a recipe that claims to be sugar-free, you always need to read it as 'added-sugar' free or 'refined-sugar' free.