You could have used macros, but that is probably above your skill level at the moment.
That time will come. I think the default controls are ctrl+Q to start and stop 'recording' and ctrl+X to replay said recording.
Otherwise you'll need to look in the controls menu.
After downloading you have to start a custom game and activate that addon.
You will probably also like the
fillcan. It recolors all bricks of the same color that are next to each other.