Get them tired
This should be your first step with them, because you don’t want to introduce them to something new like this when they still have tons of jumping around energy. Go for a nice walk, play catch, read a book together- get them pooped out.
Pitch your tent somewhere familiar
If your tent is freestanding try pitching it in your living room or a familiar grassy area. Move around freely and normally while you are pitching it. Next open up the door or doors if you have them and let Fido go in and out as they please. Another idea is to put a favorite toy, pillow, or blanket in the tent so the dog can smell they smell inside it too. Practice getting in and out together- give them treats and praise. If you can do this more than once that would be helpful.
Show them where they should sleep
Dogs sometimes need pointers about what you want them to do. They won’t know right off the bat that you want them to sleep down by your feet (if that is where you choose). Get a blanket or pillow that smells like them and show them that you want them to sleep there. Use encouragement to get them to sit there and relax. Maybe a belly rub even.
We have our dog so used to sleeping in tent she tries to sneak in all the time. Sometimes I need to unzip the tent to throw something in and she's right there trying to get in for bed time.