This is wrong question (in the headline). Unfortunately many founders begin with it and have problems (mostly, stuck inside circle of first users), because local bubble users (first users) are absolutely different from other users.
And first users are so different from rest users (lets name them Second users), that considering first users in business decisions could scare away Second users, limit business on local bubble.
Yes, you may need first users, like car gas engine need starter to make first turn, or better analogy kick-starter in motorcycle. But these additions in most cars and cycles considered only for cold start, and 100% other time they are just expensive load.
The best paradigm I seen on this problem, just start business without first users, start from second users.
What this mean, you not start making MVP for nowhere, you start with find large community, who will just buy ready product.
For example, you could start with making some additions (mods) to existing product, make your respectable brand name, and once just present your own product, instead of additions.
Most known for me example, Counter Strike started as mods to Half-life game (may be, this legend not exact, but very close to reality), its First clients was from HL community, and once people release, around CT created NEW community, and CT have enough SECOND clients, to be independent subject and they separated it to different business entity.