created surface is above original line work, how do link the two

I am fairly new to the 3d aspect of design, I do all my design in 2d layers but I want to move into the 3d world. I am learning to create surfaces but the new surface sits "above" the original drawing. How can I attach the two entities?

Cheers

Surfaces and solids are two different things. Depending on what you ultimately want to do with you CAD work, you need to determine which one is right for you.

If you do want surfaces, click on the object and pull up the properties for it. ('properties' on the command line or ctrl+1 hotkey). You should see the property of 'elevation' listed there. Compare that to the same property of the other objects that are on the plane you want things on, and you can adjust the elevations as needed.

Also, you need to make sure that you are in the proper view when you start drawing the various objects so that they behave and end up where you want them. That can be found on the menus under View/3D Views/ and then whichever of the views you want from the drop-down (top, bottom, left, right, front, back). Play around with the views and get a sense of where you are in 3D space. These are also good to know where they are so you can get this back to normal after you do a 3D Orbit. I have the View Toolbar open all the time for this reason.

Reorient your UCS. If there is a point common to both planes move the items on one plane to the other using an Osnap like endpoint.