How can I change the order of competitions in my side bar?
The ordering of competitions, within a single league, is controlled via the FixturesLive system, by whoever is the Competition Administrator for the league.
That ordering works by giving a 'display order' number for each competition. The competition at the top of the list has the highest 'display order' number. This is how competitions are ordered within the WordPress plug-in if you are dealing with a single league.
In WordPress, you'll only need to override the display order if you are mixing competitions from different leagues.
To override the display order, log in to the admin side of your WordPress site, then click on Leagues from the menu. Hover over each competition, and click 'Quick Edit'. You will see the Order value for that competition. Increase the value to move the competition up the list; reduce it to move it down.
NB this can be affected by further changes in the Competition Administrator area.