We have to conquer our own solar system first. Not war type conquer but technology type conquer.
I figure (imho) Earth doesn’t have sufficient material to produce viable interstellar travel.
We need viable mining operations on moons, asteroids and planets.
Viable Industry complexes in very high orbit or even mid-space between here and the moon will the start of it all. Alls that’s needed for unmanned transport (or manned for you classic types) from earth to complex to moon.
Conquering some aliens along the way would be good too.
Start with those runts on the dark side of the moon.