All Things Solo

• Any Game-space such as -at least- Standard FGU to keep things in one place and save your campaign. Demo FGU could work, too for test purposes.

• An Oracle or a Solo System. Think of an 8-ball. It is a Randomized YES / NO Answer Generator. We'll use it to remove the need of a Game Master. I'll provide a simple one later. But I will also explain free Mythic GM Emulator v1 in its own entry. And much later, I'll add usage of paid, more comprehensive Oracles such as MYTHIC v2, and The Solo Adventurer's Toolbox. Both are invaluable supplements for Soloing and they deserve every penny if not more.
  
  EDIT: A Solo RPG System includes everything mentioned here in one book.

• Knowledge of Soloing Ways, such as bread and butter of creativity: "Freeform Association" and "Random Content Creation Method". Also "Roleplay Styles" that'll keep you immersed & some "Combat Tweaks". I'll explain all in due time.

• Any Ruleset; such as D&D 5E or Pathfinder. They are included in FGU. Pick the one you know & like.
• EITHER Free Rule Book (Basic D&D Rules in FGU) OR paid Player's Handbook for automated PC creation and spell effects, etc.
  
  • EDIT: Check the comments.
  
  
• A Monsters Manual or at least some monster stat-blocks. Because you're also the Game Master.
• Random Generators such as the ones in Paid Oracles or Game Master Modules. Or look here.

These are more than enough, but of course, if you already have other modules, you can also utilize them. For example;

• Game Master's Guide to learn about GM side of Soloing and many random tables, as well as dungeon / wilderness creation (text) as you go.
• A Campaign Setting Guide (i.e: Sword Coast Adventurer's Guide) to "play in it as you discover it" instead of reading it like a book. I will elaborate later, in its own entry, giving you tips to create your own story in setting modules.
• Maybe a published Adventure Module. This is the hardest part to incorporate into SP for they are not written in SP-friendly manner (spoilers!). But I will try to explain how to do it and give you examples, much later in the series.
• Many free and paid extensions of your choosing for SP and ways to utilize them. I will list all of them both in topics and in their own entry.