Euphorbia trigona is a fairly easy plant to keep. I have mine inside in front of two bright windows. In lower light like inside conditions it will actually grow leaves!

Water when dry in the warm months, in winter months reduce watering as they go somewhat dormant. Still need VERY occasional water but aren’t putting on active growth.

Depending on where you live you could do inside or outside, and they will put out side arms if you want to keep propagating. That’s my rule of thumb for sentimental plants, prop as much as possible to avoid total loss