ah ok..then you can go straight to rifts...click LOAD...load the profile "greater rifts..."...next to "SETTINGS" there's a little dropdown arrow...choose combat routine (only if you are running the bot the first time)...click START...default settings on the both are suffice to get started...if you have a particular build on your characters, DB should be able to detect the build (if the build is included already) and run the routine for that build auto...you can then check out Trinity-->Config for most options...if you have more questions, just ask here
ps...you can choose other proflies to load...but just be aware that there are profiles that still need to be fixed...greater rifts, nephalem are working though...