Basic first habits to get used to in the beginning:
Aim to drink at least 100 oz of water per day (more if sweating more than normal)
Try to intentionally walk for at least 45 minutes per day. Intentional is the key word because pace will be different than a leisurely walk.
Prioritize protein in your diet. The leaner the meat choice, the higher the protein intake will be while keeping calories down.
Resistance train 3 or more times per week.
These points alone will get you started down the right path in your health journey. I can not promise success from just these things alone but it will be a great starting place for someone who does not know where to begin.
I hope these were helpful.