There are not a lot of transitions in AE because AE is not an editing app, it's a compositing app designed to create short sequences or shots. Just about any transition you want can be made by simply animating properties or using custom gradients and the Gradient Wipe effect.
Many Thanks Mr. Rick
But is it possible to export to Premier for adding transitions and bring it back for further edit in AE ?
If you do that, you're probably working backwards. The normal workflow is to edit in Premiere, then use Dynamic Link to bring the video into AE for the effects work.
Thanks Mr. Dave ,
I guess wit this one , I am gonna use key frame techniques to do the job, but for the future I 'll do the your ways and Mr. Rick's ...many thanks.