Each book has a standalone ending, so you can read them in any order. If you do want to read more, and I hope you do, there is a larger arc for each cycle, and a larger meta-narrative across cycles that will become apparent later.

At the moment you don't have much choice in where to start, as only The Year Before The End is out, but you're not committing to "having to" follow the series through at any point.

The Sovereign Earth Cycle is due to complete publication in 2021 or early 2022.

Sovereign Earth Cycle