Animating titles

Another way is to keyframe the opacity:

premiere+pro+keyframe+opacity

Open your Effects Panel and click into 'Video Transitions' from there you can open a number of sub folders all containing different transitions such as slides, swipes, etc. You can drag any of these transitions onto the beginning and end of your clip to create your desired look.

From your description you will most likely want to use the effect called 'cross dissolve' which is located under the 'Dissolve' folder. Alternatively you can type 'cross dissolve' into the search tab at the top of the Effects Panel and drag and drop from there.

Premiere Pro is complex software.  Don't skip reading the manual before working on real projects.

https://helpx.adobe.com/pdf/premiere_pro_reference.pdf