welcome to the forums
- Have you read any tutorials yet?
- next time you post a code, use the code button, it's not a big a deal with this post, but it wil be when you post a 250+ line code.

now with that out of the way;
I'm not going to give you a working code, instead I'm going to give you hints, so you can make a working code.
If I'm correct you should already have had the error message "specified angle must be between 0 and 360 degrees". This is becouse yrotate object must be in degrees. Darkbasic uses the command wrapvalue(<var> to automaticly place numbers given between 0 and 360.
seccondly you should use the sync command. It makes sure the program updates once a loop (and not every time a command is given). Your program will run smooth if you use it.
So put "sync on" at the top of the code. This tels darkbasic to use the sync method (backbuffers and such)
then place "sync rate <var>" after it. this tells darkbasic how fast to update the screen. the human eye can see 24, but 30 or 60 is recomended.
finally place "sync" at the end of the loop so it will update the screen (else you'll see a black screen).
cls 0 was nicely placed but serves no purpose, since darkbasic already starts with a black screen and when you create 3d then darkbasic uses a blue background
Last you could use a varible to store the angle, then use yrotate to rotate the object by that value.
Note: Sorry if I come over a bit strong, english isn't my native language.