When i try to download files I get an error and it says i have a case-sensitive drive despite my drive having a filesystem of APFS

You might check the APFS format of the particular volume you're trying to download files to - not the selected volume group as shown in your pic.

APFS volumes can be set as case-sensitive.

You may wish to reformat that particular volume to exclude the condition.

"APFS (Case sensitive)" and "APFS" are not the same formats. Either can be chosen when erasing a disk.

What application are you trying to install that doesn't like a case-sensitive format?

Before changing your startup drive, maybe the problem lies with that package? Perhaps some install guidance from the publisher is in order.

You will not be able to wipe that drive volume because it's part of the startup group.

To do so will require that you boot in Recovery mode, wipe the drive and Reinstall macOS. This WILL ERASE all of your data. Do create a Time Machine backup on an external drive before you start that process.

You’re welcome. 🙂

As I recall Adobe doesn't work well with Case Sensitive.