A hardware engineer just came into my office earlier with a prototype for a cheap server with a good GPU for AI tasks. He incoporated in California in 2013 and still hasn't actually gotten a product out or made sales. Meanwhile he paid 6 years of taxes * $800 = $4800. He could have bought an iMac Pro, or invested in the business in some way if he had not incorporated. You don't need to officially be an LLC or corporation for your project to be real.
If you really do need to legally form a company to separate out finances and liability, depending on what you’re doing, you might want to look at starting a Delaware C corporation (they have a minimum franchise tax of $350 plus I think a $50 filing fee). If you’re thinking of taking investment the rules and laws of Delaware are very well understood and there is a substantial amount of case law that makes it a lot more predictable to use their courts as almost everything that can happen has happened. So for certain types of companies it’s cheaper and better. For smaller things a C corporation may be overkill and an LLC or S Corporarion may work better if you do not need to raise money.