Seeking Advice on Improving Client Acquisition and Market Validation for Startups with Limited Marketing Budget

My request is rather non technical but I'm a total dummy when it comes to GTM, i'm struggling to get clients for the past 6-months, and my company is bootstrapped so the marketing budget is barely non existence. Can someone please help me out, i'd a co-partner in strategy, i do have multiple ideas, but i need market validation I'm currently working for two startups Startup A is a AI-powered cloud security platform , and we're open for free trial or early users. Our ICP is CTO, DevOps, SecOps of an early startup i.e. 50-100 employees, their pain point is that we are protecting them stay secure of AI threats. We are primarily targeting healthcare, saas and fintech. Startup B is a solution/IT company and we sell AI Agents, MVP development, UI/UX, Website development etc ICP is startups and enterprise, we've already worked in 10+ industries For now, i'm focusing only on Startup B, putting Startup A under its umbrella of services. My open rate is 45% but response rate is 1%, and no calls booked so far. Medium is LinkedIn, and i'm using my personal profile