New Venue for Discount Buyers: The region’s retail wars will heat up at 8 a.m. Tuesday when Wal-Mart’s first Orange County store opens at the Anaheim Plaza shopping center. The 155,000-square-foot store will become the Arkansas-based chain’s largest California outlet. The Anaheim store is the first of three that Wal-Mart plans to open in Orange County this year. The openings will pit Wal-Mart Stores Inc. against rival discounter Kmart Corp., which is opening Super Kmart stores (which include grocery areas) in shopping centers close to the new Wal-Marts. Opening dates have not been announced for the Wal-Mart stores at Foothill Ranch Town Center, in an unincorporated county pocket about five miles northeast of the El Toro “Y,” and at the Marketplace shopping center in Laguna Niguel.