System Data is taking up too much internal storage space.

One thing you can do is remove all local snapshots except the latest with Disk Utility:

Regarding the System Date it used to be called the Other Category which is a potpourri of files which can include:

• System temporary files

• macOS system folders

• Archives and disk images (.zip, .iso, etc. - often found in the Downloads folder)

• Personal user data

• Files from the user’s library (Application Support, iCloud files, screensavers, etc.)

• Cache files: browser, Mail

• Mail messages & attachments

• Fonts, plugins, extensions

• Safari reading list

• iTunes backups

• Crud resulting from jailbreaking your iDevice

• Game data

• Saved data files

• Call history

• Notes

• Media

• Voice memos

• Other files that are not recognized by a Spotlight search

• Media files that cannot be classified by Spotlight as a media file because they are located inside of a package

• Files created and modified by other user accounts on your Mac.

They can be located anywhere on your hard drive.

The files that you have control over are located in the Documents, Downloads, Pictures, Music and Movies folders.  You can use this free app, GrandPerspective, to find the largest files on your drive so you can determine if they can be deleted or moved to an external HD for storage.

Note: you can empty the Downloads folder after the apps and/or updates that were downloaded have been installed or applied.  Some users have found a couple of Gigabytes of files in their Downloads folder which are no longer needed. 

Are you using Time Machine? If you don't have a backup strategy in place you'll lose your data eventually. It's like driving without a seatbelt. You don't need it until you do and then it's too late.

The app is free from the developer's site but $3 from Apple:

Download GrandPerspective from Sourceforge for free or from the App Store for $2.99. You'll get the same app either way.

If you need a good external SSD go to OWC (MacSales.com) and contact their Customer Support. See what they support for your particular Mac, work requirements and budget. OWC is considered the premier 3rd party provider of Mac hardware by most of the experienced contributors here.

One last reminder: If you don't have a backup strategy get one implemented ASAP!

User wrote " Keep in mind I have a 256GB internal storage" and " For clarification, I'm a music producer and animator of sorts. I use most of the Apple Pro Apps such as Logic Pro, Final Cut Pro, Motion, and Compressor for a lot of my creativity. So maybe therein lies the problem. I am not sure though. "

To do what you would to do, would require a computer with at least 2 TB Capacity Internal Drive

Not matter how clean of an installation is kept on this machine, using the High End Apple Applications you have listed is going to an ongoing struggle.

May consider investing in a very good General Enclosure and a very good Large Capacity SSD Drive for the enclosure

I am sure @Old Toad 😎 has some very excellent suggestions on where to get them and what to look for as per your machine Specific Configuration

Then, follow along from this User Tip to Install and Run the machine Off the External Drive

Use an external SSD as your startup disk with your iMac or Mac mini

Trying to upgrade the internal drive, as PRP_53 pointed out is very risky as well as neigh impossible. You'd be so much better putting your files on external drives and just have the system and apps on your internal drive. I have 6 external SSD for my data files in this configuration:

It's easily expandable and changeable. You can get faster SSDs by having them in their own cases with the appropriate chip. This works for me.

Use wrote " As PRP_53 suggested I should have at least 2TB of storage for these pro apps. In relation to both of your messages I am thinking of upgrading my M1 Mac mini to have more internal storage space. I do have enough external space but not internal. There is actually a way to do this internal upgrade which was demonstrated by a Luke Miani video. Upgrading from 256GB to 2TB is technically possible on the M1 line of Mac minis. I am in contact with the same person that helped Luke Miani upgrade his system. I know it will void warranty if I do this modification, but I got my mini used anyhow, warranty expired when I bought it LOL."

All M Class Apple Silicon Computer have the Internal Drive Soldered to the Logicboard as is the RAM

Buyers oversight, at time of Purchase

IMHO - There has been sufficient advise offered for the User ( you ) to make an informed and educated choice what remedial actions are required for this computer.

The suggestions have been put forth on a volunteer basis, in good faith and in the best interests of the computer.

Best of luck on whatever you choose to explore