At lot of advice for solo founders is from people with survivalship bias, vocal sales biz dev and people that had right connections. I think tech solo founder path is different and in today market is very difficult. I can give advice on things that I did wrong so far. Avoid direct stripe integration and complex subscriptions models this would be time sink, use merchant of record and as simple as possible subscription model. Ignore everything non essential for product like usage charts, account management etc. Get decent designer but limit his scope to product features say NO to design system and custom components, use off the shelf UI toolkit with minimal customisation. If you want to raise wait for more traction and avoid startup conferences, better to go for your industry conference instead.