I just did an at home Brazilian (NADS BRAZILIAN WAX) and I used ONE wooden spatula the whole time!! Will I get infection & can I use witch hazel aftr?

Witch hazel. I don't know if you will develop an infection. Many witch hazel products contain alcohol - that could cause a burning sensation on broken skin.
Probably not. Keep the area clean, wash with warm soaks and non detergent soaps. I would prefer a topical antibiotic like bacitracin , Neosporin or triple antibiotic Ointment on the area for a few days until all the open areas are healed. I think its better than witch H. Make sure you are not allergic to any of these antibiotics if so don't use it.