Do not confuse polar alignment with GoTo alignment (aka calibration). Polar alignment makes sure the RA axis of rotation is parallel to the Earth's axis of rotation. GoTo alignment tells the computer the orientation of the mount and telescope relative to the heavens.
You will be able to send the scope/mount to park, save the settings by hibernating, and power down. On power up, if the scope has not been moved, you will be able to accept the saved settings, and begin. Problems take place under three circumstances:
1) The scope has been moved.
2) There was a power failure, or some other kind of tracking failure, before parking and hibernating.
3) After several hibernation cycles, or a few weeks even if not used, the mount's GoTo must be realigned.
You can set a software limit in the handset to have the mount stop tracking, and if you are guiding using the ST-4 outlet, it will also stop (this is a Celestron feature, not all mounts have software limits or monitor the ST-4 port). When the scope hits the limit, it will loose its alignment, and you have to realign the GoTo. The problem with the handset limit is it assumes you know what you are doing and you can see it. If you manually slew the scope locally, remotely through NexRemote, or remotely through the ASCOM driver, the scope will go pass the limit, and if the scope can hit something it will.
German equatorial mounts (GEM) cannot go much past the zenith without hitting something. Once you have gone past zenith one of three things must happen:
1) you did not set the RA travel limit correctly, and the camera hits the pier usually breaking something.
2) you set the RA travel limit correctly, and the scope stops, but looses its GoTo alignment.
3) you perform a meridian flip.
A meridian flip is performed in the following sequence either manually, or if the software supports it under software control:
1) stop camera from exposing
2) stop guiding
3) perform a go to the same position you were pointing, but on the other side of the mount
4) make sure you are pointing at what you are shooting, a stock CGEM, using Celestron's all sky polar alignment (ASPA) routine in the handset, and a standard 3+4 star alignment typically will not be accurate enough for centering a 8" f/10 scope with an APS-C sensor, so something must make a correction.
5) typically an SCT will encounter a focus shift called a "mirror flop" when a meridian flip takes place, and will need to be refocused (not all automatic focus systems will handle mirror flop, also some auto focus systems require pointing to a focus star on the same side of the mount as the target to refocus)
6) find a guide star
7) start guiding

start camera exposure sequence
There are several ways to point accurately to center the target:
1) make trail exposures and move the scope to the right place manually
2) use plate solving software
3) perform a highly accurate polar align no more than +/-2" error (very difficult, and requires drift alignment) and use software sky modeling. Sky modeling requires plate solving for its calibration, this is not an either/or situation.
Plate solving has the computer determine where the scope is pointing. Plate solving software needs at least 20 GB of disk space for star tables and a fast computer because it is computationally expensive. The sequence for plate solving is:
1) tell software RA and DEC coordinates desired.
2) software takes over imaging camera and takes a picture
3) picture is processed
4) picture is compared to a database of stars. This can take a long time with a slow computer.
5) software determines the relative difference between target and actual pointing
6) software commands mount to move to new relative position
7) until the accepted level of pointing error is reached the software will repeat steps 3 through 6

when error tolerance is reached software tells mount where it is pointing (this is called syncing the mount)
9) software notifies user or calling program
I have taking the time because hitting the tripod or pier with your camera or diagonal and eyepiece is a common unhappy experience made much worse when unattended. As you can see there is a lot of detail to learn. This is not the place to learn it. So I will leave you to your hands on experience.