Converting models for import

Hello, I’m a total noob to using UE and although I have experience with CAD modeling I’m stuck with simple things like importing models. Can anyone help…
I am trying to import some furniture models of my own so I can play with rendering. I read you need .fbx or an .obj to convert into .fbx but I’m struggling finding an easy way to do this…I don’t have autodesk 3D max so this is not an option. I can convert to the following file types:
.acis
.model
.dxf
.dwg
.igs
.jt
parasolids
.stp
.vda
.stl
.zpr
Any help would be greatly appreciated,
thank you

Here are some videos to import .fbx .Generally I use this file format as it is mostly used.

https://www.youtube.com/watch?v=_FgedJWInL0

but I would say use .fbx export from 3ds max. here is the documentation

https://docs.unrealengine.com/latest/INT/Engine/Content/Types/StaticMeshes/HowTo/Importing/