Making low poly cars is best to use an alternative software such as blender I wouldn’t recommend payed programs if you feel the need to but blender is a free, open source that a lot of developers use nowadays: I think it doesn’t matter what software you use for modeling whatever one suits your liking.
There’s 100 YouTube guides, tutorials that will show you step by step process on how to do it! I recommend using the 2.8 version or you could use the old version whatever one your comfortable with.
Try watching beginner tutorials since your new or wanting to learn the software blender gurus tutorial (donut & mug one) is a great place to start, it’s incredibly informative in terms of learning the basic tools, techniques, and workflow of blender. He also goes into more detail and explains a lot.
Here is a few topics about tips and tutorials and overall useful information that’ll help you along the way on how to get started (Learning the software basically):