Separation anxiety can be difficult for puppies. If you know you'll have to leave them for long periods during the day, you can start preparing them for alone time early. Don't make a big deal of coming and going. That means don't give them extra attention right before you leave or immediately when you get home, which could make them anxious as you prepare to leave or overly excited when you return. Instead, try giving them an activity to do while you're gone, such as a treat toy.
When you get back, you want to greet your puppy, but try putting away your stuff before giving them attention to keep them calm and reduce separation anxiety. If you don't want your dog to jump on you when you get home, turn your body away when they jump. This will teach them that they will receive attention for good behaviour.