Using the select tool (Shift+S), select the entire building by dragging a box around it in the 2D views. You should check all 3 views to make sure only the building is selected (use a large grid size at first, then decrease to fine-tune your selection). You can now move the building around, or even resize it.
While it’s selected, you may also want to Group it together (Ctrl+G) - this way you can just click on it and move it around all you want with ease.
For a beginner’s tutorial for Hammer, you can check out this page.
Thank you so much XD
No problem! ;D