I'm going to replace my host os on my shitty laptop with Linux specifically puppy Linux or alpine Linux from scratch and I need to know how will I get started and make it easier for myself, I use a HP notebook 540
You might want to think twice before using unique, niche distros like GoboLinux, Alpine, or NixOS. PuppyLinux doesn't look like a proper distro, more like the equivalent of EndeavourOS or Artix. Since you're using Linux for the first time, why not use Linux Mint, Ubuntu or Fedora?
No not really. Gnome for me is about 2.5 gigs of Ram, XFCE 700 megabytes and the CPU load also is way lower. XFCE can be heavy or light depending on how you configure it