Have a look on the packet of teacakes and see how much carbohydrate is in them!!When you get your meter the thing to do is test first thing in the morning,before eating then,test two hours later and see what you have eaten has done to your blood sugar levels.Keep a food diary so that you can check which foods are making your blood sugar levels go up.Do this for a week testing before and two hours after every meal and you will soon see which foods that you eat are suitable or not.If ,when you test 2 hours after,the reading is much the same as when you tested before eating then that meal was OK.
Have a good read round the forum and you will pick up lots of helpful advice and ,keep asking questions.