Hi Noshi Akhter,
Thank you for using our services.
Can you please be more specific on that kind of errors you are getting. This way we would be able to take a deeper look into your issues and provide you with solutions. Some information on the system that you are using would also be useful (what OS you are using, IIS version).
In the mean time can you please take a look at Bullet Proof Guide to Installing Sitedinity 3.x
. Just to make sure that you have followed the correct steps setting up your IIS, and installing Sitefinity. There should be problems with the trial version, since the only thing that differs it from a licensed version is that you do not have a license key. All the functionality is the same.
I hope that by just following the install guide steps, you will solve your problems. If otherwise we will be more than happy to assist you.
the Telerik team