Had tooth extraction and the socket has like a whitest plug in the middle of it kinda over the blood clot. is just the gum healing or is it infection?

Maybe just food part: Plaque can form in a short period of time. Don't rinse or gargle if you are in the first 24 hours. Dislodging the blood clot can lead to a dry socket which is extremely painful an doesn't show up immediately after the clot is lost but rather 2 to 7 days later. After 24 hrs it is safe to return to normal activities.

Sounds normal: If no other symptoms probably ok. If you're not sure, ask the dentist or oral surgeon that did the extraction to take a look.

Time since extracted: The duration of time from when you had the extraction, the severity of the extraction- was the tooth bony, soft tissue impacted, at a bad alignment that it had to be sectioned (cut, ) etc., may determine the type of healing. The white spot may be what is called granulation tissue and is a phase of healing. If in doubt, go back to the dr. Whom extracted the tooth rather than wait.