First you need to fix your quick access tool bar. 

Pull down the arrow at the right of the quick access toolbar and turn on the menu bar.

This will allow cad users from earlier versions to enjoy good portion of the functionality they are used too.

Next pull down the arrow at the right of the quick access toolbar and uncheck each of the items that are on the bar.  This will remove all of the items from the bar.

Now you will have to re-check the items that you want on the bar.  The items will populate the quick access tool bar in the order that you check them.  Please populate them in the order that you are used too.

Turning the command line window on is not necessary, however it will display useful information and follow the commands have been used.  This is handy when you want to undo a long line of tasks or view a dimension of a distance you just calculated with distance inquiry.  If you use text commands this can be a very useful tool just turn it on with CTRL-9 and dock it at the bottom by dragging it there.

Now that we have the menu bar turned on lets change some settings that will help us in the future.  Please navigate to tools and then options.  Then click on the display tab. on the display tab.  You should have a windows on your screen similar to the one to the left.

(The other way to get to the options window is at the bottom of the right click menu interface when you right click in the drawing window.)

Make sure you check the Display File Tabs check box and then check the Display Layout and Model Tabs check box.  Then click ok! These changes will add tabs at the top of each drawing to allow you to close them individually without closing Autocad. You will also now have tabs at the bottom of each drawing that will allow you to format layouts and draw in model space.

Command Locations on the main Autocad 2015 Menu Ribbon Tool Bar

Drawing Section

This allows you to draw everything that was on the old toolbars.  Just remember you may have to use the pull downs on the side to access some of the tools. Also when you expand the arrow at the bottom of the draw section you can pin it at the bottom left to keep the section expanded.  This may be handy while you are learning where everything is in Autocad 2015.

 

 

 

Modify Section

The modify section still allows you to mirror, move, copy, fillet, chamfer, rotate, scale, trim, extend, array, stretch, etc. Instead of being listed on the modify toolbar it is listed on the main toolbar under the home tab in the second section.

 

 

 

 

Annotation Section

The annotation section of the home tab on the main toolbar allows you to add leaders, linear dimensions, aligned dimensions, tables etc. Again this is right on the main home tool bar, to make this easier to access.

 

 

 

 

 

Layers Section

The Layers section of the home tab on the tool bar allows you to open the layer tool pallet, thaw/freeze layers, turn layers on and off, and even allows you to save a layer state or manage one of your existing layer states.

 

 

 

 

Block Section

The Block Section of the main home toolbar allows you to create blocks edit attributes, define attributes etc. This section will also allow you to edit a dynamic block in real time if you need to add an additional width dimension or wall thickness dimension to a door.

 

 

 

 

Properties Section

This section allow you to change the line type, color, line thickness, transparency, or toggle the properties tool pallet at the arrow in the bottom right corner.