Quick version:
- Install latest Java
- Install latest Minecraft Java server
- Play vanilla Minecraft
Rabbit hole:
- Bedrock / Java version differences
- Modpacks, mods and Minecraft version differences (1.12, 1.20) require different Java versions.
- Official server vs 3rd party software (papermc, purpur…)
- Publicly open server vs firewalled
Thanks for making these posts!
Just to add more info on those images you found for Dolphin. The original art without the text is from this artist https://www.artstation.com/pierreroussel/albums/8482338. I love them.