Technically the correct first thing to do is to make the manufacturers release the relock keys for relocking the bootloaders of extant hardware (say, the Moto G6 for an example). Having MicroG or whatever is not much useful if there's not going to be a feasible phone on which to install, so getting extant phones to become relockable with AOSP distros would be priority. And the way the economy si going and the RAM chips are not, forcing everyone interested to have to buy a whole new phone is not a smart choice.
Once the relock keys are out, fund All the Things. Lineage, Calyx, MicroG, what have you.