struggling with content planning, how do i even start?

i just launched my first small SaaS a few weeks ago, and honestly, i'm totally lost when it comes to content. we've got some initial users from ads and word-of-mouth, which is great, but organic traffic is basically zero. everyone keeps saying 'content is king' for SEO, and i totally get it, but i don't even know where to begin with content planning.

i've tried brainstorming, but it just feels like i'm guessing. i don't know how to pick topics that actually matter to my audience or how to structure them for search engines. its like trying to code without a compiler, you know?

// my_content_idea_generator.js
function planContent(targetKeywords) {
  if (targetKeywords.length === 0 || targetKeywords.every(kw => kw === '')) {
    return 'Error: No actionable keywords. Content strategy initialization failed.';
  }
  // ... imagine complex keyword research and content mapping here ...
  return 'Success: Generated 10 blog post ideas based on competitor analysis.';
}

// my current attempt:
let myKeywords = []; // yeah, i know, i'm stuck here
console.log(planContent(myKeywords));
// Output: Error: No actionable keywords. Content strategy initialization failed.

so, for someone completely new like me, what's a simple, step-by-step approach to build a foundational content strategy? i'm really looking for a clear content marketing framework. what are the absolute must-have tools or initial steps i should focus on to actually get started?

i really appreciate any guidance from you experienced folks. i'm kinda waiting for an expert reply to help me out here.