A new garage door install is not a good first DIY project, and we'll say that plainly. The door itself is a torsion-loaded panel under enough spring tension to break a bone if the winding bar slips - that risk doesn't change because the house is in Mount Prospect instead of anywhere else, but it's worth stating once, clearly, rather than assuming it's obvious.
What you can reasonably do yourself: clear the opening, remove trim you don't want damaged, and measure your rough opening width and height before we arrive so the estimate conversation goes faster. What you shouldn't do is disconnect an existing torsion spring, attempt to set a new one, or wire a new opener into an outlet that isn't grounded correctly - houses from this era sometimes have garage wiring that was never updated when the opener was added years later, and that's not a job to discover mid-install. If in doubt, leave the spring and the electrical to us and handle the parts around it.