Laptop out of space … could I create a storage partition (separate from the back-up area) on Time Capsule?

Not sure if I understand what you are asking correctly.

The Time Capsule backs up everything on your Mac, so you have two copies of your data......one "original" or "master" copy on your Mac and the other backup copy on the Time Capsule.

If you remove any "original" or "master" data on the Mac......then it follows that you will have only one copy of the data left on the Time Capsule.......AND.....you will have no backup of that data if the hard drive on the Time Capsule fails.......something that would not be unusual if your Time Capsule is 6-7 years old or older.

It would be much better if you simply added another USB drive and connected it directly to your Mac.......and then move the data that you want to move off of the Mac over the USB drive. Then........Time Machine will back up both your Mac and the data on the USB drive over to the Time Capsule. So, you still have your "original" or "master" copies in one location and separate backups of everything on another drive.

The bottom line.....which users unfortunately often seem to forget........if you have only one version of your data in one place or location.......you have no backup.

As far as partitioning the Time Capsule is concerned........it is not possible to set up traditional separate partitions on the Time Capsule drive unless you physically pull the hard drive drive from the Time Capsule, copy everything on the Time Capsule over to another hard drive, erase the Time Capsule drive and then set up separate partitions on the Time Capsule drive. Once that is done, the data on the drive will need to be copied back over to the Time Capsule drive, and then the Time Capsule drive will need to be reinstalled on the Time Capsule. This type of undertaking is strictly for the pros.

It is possible to create what is known as a "disk image" on the Time Capsule to reserve a certain amount of space that you specify, but unfortunately this is a complicated process that goes beyond the scope of the support that we can offer on this user-to-user support forum.

In other words, we can tell you "how" to try to set up a disk image on the Time Capsule......see the link below.......but we will not be able to offer support if things go wrong. You can get an idea of the process by reviewing the steps in this document:

Create a disk image using Disk Utility on Mac - Apple Support

Sounds as if I need to get …

• either another USB drive (are you talking about a high-capacity version of what we used to call a 'thumb drive' or something bigger that just happens to plug in via a USB cable?)

The USB "drive" could be virtually any type of storage device......thumb drive, spinning drive, or solid state drive (SSD). The solid state drive delivers the best performance in terms of access speed, but if you will be storing data on the drive that you don't regularly need, it might be hard to justify the extra expense of the SSD.

Just remember that the USB drive will need to be formatted the same as your Mac's hard drive, which is probably Mac OS Extended (Journaled)......if you want to use Time Machine to back up the USB drive along with your Mac.

• or a new MacBook Pro. Mine is pretty old.

Normally, I start to think about replacing my laptop when it is in the 7-8 year old range, I new MBP with a much larger hard drive would certainly be the easiest way to go if the budget permits.

Good luck!