Running out space for /var, what todo? Can I solve this?

Hello,

I'm not a guru on linux but I try to learn it and try to succeed.

I have installed Fedora 31 without any further reason. I have been googling for the size of the different partition/mounting points.
Here my overview:
- boot: 500 Mb
- /: 10 Gb
- home: 50 Gb
- var: 4 Gb
- swap: 8 Gb

I'm developer and I have installed by myself:
- Apache
- PHP
- MySQL MariadB
- Netbeans

Everytime i update the software there was the message /var is running out of space or there is not much space left!
I'am more or less already in trouble. I have two kernels on my system.

I was playing around with docker to find out how it works. I have docker running with "Hello world".

The next step what I just did is "docker pull jenkins", but that is not possible anymore.

So what is the best thing todo in my case:

• Can I change the size? If so How
• I see most the diskspace is used by /var/cache/PackageKit (docker)
• I read somewere to make my home dir 50Gb now I'm doubting, why 50 Gb?

I hope that someone will advise me what the best thing is todo? Hopefully not to install complete Linux again. I have made it multiboot and there is some fysical diskspace (80 Gb) left that I can use.

Thanks in advance,

Nico