I second what PJ said about concentrating on the gardening skill. I have found for myself, that if I have my sim garden every day that the gardening opportunities come my way faster then if I am doing other things with my sims. I currently have a sim that is working on just 4 skills, gardening, cooking, fishing and handiness. My sim gardens everyday, even when I just started the game up. He would go around town and harvest until his own garden took off. He is working on the 10 excellent cheeses at the moment and then will be working on the steak and burgers. Good luck with getting your opportunities!!