The easiest way, although it might not work with your tablet, would be to try Towelroot. It uses a kernel exploit to gain root access. You will probably have to go into your security settings and allow apps from untrusted sources, then you can install it. I'm not familiar with your tablet and whether it has a locked bootloader. Also, note that Denver tablets aren't officially supported, but it's still worth a try. https://towelroot.com/
There are some other alternatives to Towelroot out there, but I haven't personally tried them and therefore can't recommend them. They may work fine, but I just don't know enough about them to vouch for them.