Buildapc

Hey, everyone. I'm building my first PC and would like to ask for some help. I've always been more of a console guy, and all my PCs so far have been pre-built and intended mainly for office stuff, so I have zero experience with this.

This is what I had in mind:
https://de.pcpartpicker.com/user/kablurk/saved/hxR6Bm

It's around €700. If I can gain a significant performance boost for paying a bit more, I can do that. For example, I'm considering getting 32 GB of ram instead of 16, although that would probably be overkill for my needs. Other than that, I'd like to keep a balance between low price and parts that aren't already outdated in a few months.

As for my requirements:
I want to try out Linux, and I've read that AMD GPUs are more compatible with it than NVIDIA cards.
I'm not much of a gamer anymore :( at least at the moment. So I don't need games to run at a 4K resolution or triple digit FPS. If modern games run at around 60-ish FPS for some casual gaming, I am more than happy. I checked some system requirements for a bunch of emulators, and they should also mostly run fine (I think).
What's confusing to me is that the RX 6500 XT only has 4 GB of memory. Would an RX 580 with 8 GB make a difference in performance, despite being older? (Pricewise they are almost the same)

There are two motherboards in the list. One of them gives me the following warning:
"The ASRock [...] Motherboard supports the AMD Ryzen 5 5600G [...] Processor with BIOS version P5.00. If the motherboard is using an older BIOS version, upgrading the BIOS will be necessary to support the CPU."
Is this a big problem or a complicated process? Would you recommend just getting the other, slightly more expensive board?

Any feedback is much appreciated. Thank you!