In a democratic union, meetings are where the business is done, and where all members have the right to have their say about how the local conducts its affairs. The bargaining unit meetings concern themselves with everything relevant to the goings-on in the workplace covered by the unit.
Local meetings are where decisions are made concerning the local as a whole.
If you aren't at the meetings, you can't assert your thoughts and opinions on how the local is run. There are two excellent short works on how to conduct meetings. Please look at the first to links to the left. Familiarity with both of them, especially the Local's by-laws, are essential both to understand how the Local runs itself, and to make changes to how the Local functions and deals with various issues. This site now has the minutes of the previous Local meeting.