Nearly all Linux packages you might want to install - work with nothing special required. Migration to ARM earlier this century made vast majority of open source software portable. Precompiled x86-only surely will not work.

Debian officially supports RISC-V and is about there[0].

Whereas qemu-user will run e.g. x86 and arm binaries, should you ever need to.

This recent review of VisionFive2[1] has a little more info. There they even run popular games via x86 emulation.

0. https://buildd.debian.org/stats/

1. https://boilingsteam.com/vision-five-2-board-review/

Not an expert, but I think anything compiled for the ISA implementation you have should work.

If there's an issue with RISC-V it's that it's not one ISA with additional instructions accumulating across generations (which I think describes x86), it's a core ISA with a variety of extension blocks that might or might not be present in your implementation. I think this means that any random RISC-V binary stands a greater chance of not working on a chip you've bought than e.g. any random x86 binary with an x86 chip.