Hi Amy! Building a lightsaber at Savi's Workshop is one of my favorite experiences in Batuu. We did this when it first opened and my kids absolutely loved it. I completely understand not wanting to carry that lightsaber around all day as it can get a little cumbersome. Luckily, each build comes with a handy carrying case that makes it easy to bring along with you for the day so that you don't miss out on some great photo opportunities around the park with your lightsabers. All of the rides will allow you to either carry it on or leave it with a cast member while you ride.
Locker rental is available at Oscars Service Station but they only have large sized lockers which do not fit the fully assembled lightsabers. A great option if you don't want to have to worry about the lightsabers until you get home is to take a few pictures around Star Wars: Galaxy's Edge and then head over to
Droid Depot where they offer shipping services. They can package up your lightsabers and ship them directly home so you don't have to worry about figuring out how to get them through security or pack them in the car. If you want to keep them for the duration of the trip, you can enter and exit Hollywood Studios throughout the day so you always have the option to take them back to your car or to your resort then hop back in to enjoy the rest of your day.
While you are in Star Wars: Galaxy's Edge don't forget to utilize the
Star Wars: Datapad with your kids. It is a fun way to interact with different park elements and you will have a blast exploring Batuu with it.
May the Force Be With You
Jenna