B2B SaaS Google Ads long tail-keyword Strategy Sparring

Here's an overview so you can judge whether this is a fit. THE PROJECT (Phase 1 = a paid test sprint) I'm launching a bootstrapped new B2B SaaS product and want to validate it through Google Ads, using... (Budget: €150 - €500 EUR, Jobs: B2B Marketing, Google Ads, Keyword Research, Marketing Strategy, Search Engine Marketing)