Yes a cockapoo can be left alone as long as they are used to the home they are being left home alone in.
If the cockapoo is not used to the home yet then you should put them in a cage inside the house to keep them safe and make sure they have plenty of water and have been fed.
You can leave the cockapoo alone in the dog crate for 8 hours but no longer than 10 hours at a time.
If you're gonna be gone longer than 24 hours then have someone take care of the cockapoo or take the cockapoo with you if you're traveling.
When a cockapoo is a puppy they don't do much good at home when they are alone but as they get older they can be left alone without issue.