One of the options that will help optimize and facilitate the editing of your work is the option to group elements. It will allow you to move, rotate, change color, or take any other kind of action on a single group.
In order to make a grupo, you'll need to have multi-select or in other words, select the elements you wish to make a group with.
To multi-select, you need to hold down the control/command key or the shift key and click on the objects you wish to select.
You can also drag the cursor to make a selection box appear that will allow you to select elements that are included in that box.
Once you've made the selection, you'll need to click on the Group icon on the toolbar.
Once you've created the group, you can edit the elements in it together.
To ungroup the elements, you just need to select the group and re-click the icon Group or the icon that appears in the group, in the upper-left corner.