Trying probably isn't going to be enough, you have to learn the tools. Modeling programs have to be somewhat complex to allow people to create a endless diversity of objects or sceens.
If they where easier to use then the user would lose control over the modeling. The best thing to do is pick a modeler that you wish to learn and read tutorials (be it payed or free internet ones), help files, and most of all practice.
If your looking to make just landscapes or terrains geoscape3d is pretty decent for the price.
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