Dollies are expensive and also slow to set up and work with. For this reason most filmmakers working with DSLR / DSLM cameras opt for sliders or handheld stabilizers.
If you are going to work with a big, cinema camera set-up, though, you will need a dolly for the slow long super smooth tracking shots.
Unfortunately, I have yet to find an affordable and good dolly. For bigger productions, I just rent a Matthews dolly, or a similar reputable brand.
If you are not able to rent, you can go the DIY route. This is what I did several years ago. In this article I show step-by-step how I built my dolly.
To get camera movements that are not only horizontal, but also vertical, you will need a jib or crane. Here is my favorite one from Konova.
Another option that I like is the jib from CAME-TV. You can find out all about it here.