"I'm trying to take everything in and be calm but I'm trying to get here again, do well, impress and hopefully get another chance," he told Sky Sports News.
"I'm hoping I'm going to be here for whoever England are playing. If my style suits Scotland that's better for me but I want to be here for whoever were playing.
"I'm always confident I can score goals if I get a chance I'm confident I can take it. My focus is just to play well and if I can score a goal as well, then that's brilliant.
Lambert spent 10 years in the lower divisions and hopes his call-up can serve as an inspiration to others.
"I hope it does send a message I never gave up hope, hopefully it sends out the message that if you are performing you'll get a chance," the 31-year-old added.
"Even if I didn't get called up for Scotland I would have been determined to get myself in before Brazil."