Just try and bootstrap for as long as possible. People think they always need money but if you are building a SaaS product you likely do not for a while. If you are trying to build SpaceX and launch rockets, you should not even care about the money but about the mission. So you will have to give up lots of equity to get where you want if your goals are super crazy.
We are currently bootstrapping and growing our userbase to have our revenue fund our business. The freedom we have because of not having an investor is priceless for how we want to change the hosting industry.
Like others have said, it comes down to being scrappy and bootstrapping at the start to validate your idea amongst customers. Once you prove your idea is valid, you can seek external funding to scale but at the start, just put in whatever you can on your own and see where the idea takes you