Whisk together the olive oil, lemon juice, the red wine vinegar, the minced garlic, the oregano, the salt, and the pepper in a medium bowl until emulsified.
Cut the pork loin into 1-inch cubes, removing any large fat pieces.
Add the pork to the marinade and coat each piece thoroughly.
Cover and refrigerate for at least 2 hours but no more than 8 hours.
Soak the wooden skewers in a dish of water for at least 30 minutes.
Thread the marinated pork onto the soaked skewers, leaving 1/4 inch space between pieces.
Preheat your grill to high heat (450-500F).
Place the skewers on the hot grill and cook for 3 minutes without moving.
Flip and continue cooking, turning every 2-3 minutes, until the pork reaches 145F (about 10-14 minutes total).
Remove from the grill and let rest for 5 minutes.
Serve hot with the pita bread, tzatziki, and lemon wedges.