when i try to look for a software update it says an SSL error has occurred and a secure connection to the server cannot be made

Above is correct.

Somebody likely installed an add-on VPN app.

Remove it.

The VPN client here is seemingly also potentially intercepting and decrypting and processing even your secured network traffic.

Is the computer connect running behind a Commercial VPN ? If so, connect directly and without the VPN interfering with the Normal Operation

I am guessing that you are using Wi-Fi. If so, it is important to understand that Wi-Fi is too slow for these very large downloads and corruption often occurs. Can you connect directly with an Ethernet cable? That should solve the problem. If not, try moving your computer closer to the modem. Anything else to share that would be useful to know?