A similair alternate to Roblox Studio?

Hello, as we all know, Roblox is probably on the brink of death. In my perception that is.
And so, since I do all my 3D modelling work on Roblox Studio [Mostly building and modelling]
I'd like to prepare for the outcome of its... fate. Thus, I ask you all if there are any alternate [Free or cheap] websites or programmes I can use which have similair toolbox actions to the ones in Roblox Studio. Preferably.

If there doesn't appear to have toolbox similarities, thats fine by me.
Also, blender is an instant-no for me. It is too much for my poor brain.
And I've used TinkerCAD before. Let's just say it can't handle Unions or Separations very well...