New user having basic problem

Could someone please help me. I am a new user and have tried to write a very simple score in 4/4 time just to find my way around things. In the very first bar I have tried to enter quavers (4 x groups of 2 x joined quavers), however I can't seem to get them in groups of two and they always automatically join into groups of 4. I know this will be a simple fix but I just can't get it. PLEASE HELP BEFORE I GO CRAZY