load test in soapui

I am using soapui 5.2.1 (open source) where i want to do load test on my rest api request.

so my requirement is want to send  a particular load/thread (virtual request/user) request after a particular time .

E.g. 1 rest api request ..thread 10 send after every 10 seconds ..till around 30 minutes 

so please request you kindly guide me how to do same

which load test i want to use ....simple/variance/thread etc..

and what assertion need to add ...max errors/set max/tps etc...

Thanks

dev.