I'm still very new to Carrara so this may be a fairly simple question.  I started out by learning to set up and light interior scenes which as it turns out is one of the simplest things to do in Carrara since it handles DAZ people and objects, in most cases,  without problem and even does an admirable job on posing them.

Last night I decided that it was time to try my hand at building an out doors scene.  I started with a preset then modified the shading of the terrain to what I wanted without problem.  Then I tried to add a tree.  I dragged and dropped the tree from the objects menu and it shows up in the objects list for the scene but I can't find it.  I panned in a loooong ways panned out a loooong ways and same for up and down.  Never could find the tree.
     If I start by putting the tree in first the tree ends up being H U G E and when I drag and drop the terrain it's so small it isn't visible.
Is there some way to get Carrara making items that are an appropriate size?
Also is there a way to get Carrara to centre all objects added to a scene?
I have had a similar problem with indoor scenes.  I had to start with a figure rather than a setting or lose the figure when I drag and drop it into the scene.