Hi Jerry, welcome aboard.
In general, "Submit" saves the changes you made in the tool and the changes are represented when you actually start drawing. Eg if you open the wall tool and type a wall height, click submit and then left-click in the model space, the wall tool is now active at the height you have selected. Simply click in several locations and double click the last point and you will notice the wall has drawn at the input height. The wall tool will still be open and the next wall you want to draw may be higher so you type in a different height> Submit and the next walls drawn will be at the input height. This is the same for all tools and this works for every change you make including materials.
If you want to draw a window select (Spacebar is the short cut for select or you can right-click the wall and choose +Windows/doors) the wall you want to add the window to, select the window type/Height/colour/ETC push Submit and this window type will save for next time.
In Short, the Submit button remembers your choices/changes, have a play you won't break it. If you are using Windows
you only need to click once in the model space and the first click will be the location the wall is drawn from. If you are using Mac
the first click in the model space is to active the model space and the second click is to choose a start position.
1. Select wall tool
2. Select the first wall icon
3. Change walle height
4. Left click Submit
5. Left click in the modelling space PC
and that is the position your wall will start drawing from Mac
left click model space again to select wall start position.
6. Move the mouse and double left click and a wall will be drawn.
7. Change wall height in the dialogue Left click Submit and repeat steps 5. and 6. and you should now have 2 walls drawn at different heights.
A good tip is: Watch the tutorial inside each tool, it's the orange question mark at the top right-hand side when watching pause and then do the action. Once you get used to the way things work everything becomes a lot easier.