I got my wisdom tooth extraction yesterday, after that I rinse my mouth with water because of the blood, is it safe?

Follow instructions. I would assume that you were provided with post-op instructions, written, verbal or both. Rinsing is usually recommended- salt water, etc (no straws.) call the office and clarify if need be.
Normally, Yes. Unless specifically told not to, we normally tell patients to gently rinse with warm water beginning the day after any extractions. You can add salt to the water but studies are divided on whether the salt actually does anything. It is normal to see a slight amount of blood in when you spit for 2-3 days after an extraction as well. When in doubt, contact the doctor that removed the teeth.