> Was there a lot of warmongering in russia in preparation for starting the war in 2022?

It didn't start in 2022, it just entered a new phase. This conflict was already going since 2014, and the callings were on the wall the whole time. Warnings regarding Russia under Putin are going back at least 2 decades, it was all speculated and to some degree known where he was going to.

> Because from what I saw wars tend to pop up all of the sudden

Usually not. When they specifically happen is often sudden, but wars are usually the result of long processes. Most of the time, it's well known to the people who are involved and informed what's going on, and it just needs a single spark for a situation to explode in the predicted way.

Take the USA for example, the fears about a civil war which are around for a while now. It might happen or not, but when the country explodes, then it wasn't a sudden development happening overnight, which nobody could have seen coming, but the result of a long-running process which was heating up the political climate.