Newbie with Question Regarding Print Time & Slicing

Hello everyone. I’m new to this community and new to 3D printing. I have previously used 3-D Hubs for printing, but just this week I ordered an Ultimaker 2+ Extended. I’m excited and a little nervous.

I’ve modeled a print and when I load it into Cura it tells me that it will take 49 hours to print. I think I’ve heard something about slicing prints into pieces, but am unsure about how to go about doing that. If I slice them then I need them to come back together in the end. Is there a glue that’s used? Is there a way to somehow model “clips” or “plugs” to make the pieces fit together?

I’m looking for some insight into how to slice this object up to reduce print time, but yet make it still be secured together as 1 object in the end. I hope that makes sense and thanks in advance for any insight you can provide to a noob!