Here is a simple method, but it requires you to play a bit with this method, to really get comfortable. (This is not the only method to accomplish what you want to do, but is one that you may understand easily)
Create one of your "Fill" or inside polygons, according to the size and shape that you want to fill the target object. With that polygon selected, hit the '+' (Plus) key on the numerical keypad. What this does, is to duplicate your polygon and place it on top of the original. Now select the duplicated polygon and move it to the right, by some distance.
Now to make a row of polygons, all the same, you need to open the Blend Docker (Put a checkmark on the menu item Windows->Dockers->Blend). Now select both polygons that you just created and then on the Blend Docker, run the spinner count up/down to a desired number. Click on the Apply Button. If the number of polygons are too many or too few, then run the spinner up/down and hit Apply, again, keep doing this until you are satisfied with the density of polygons.
To create a field (or large area) of fill polygons, while you have the blended line of polygons selected, click on Arrange->Break Blend Group Apart (or hit Ctrl+K keys). Now select the row of polygons and hit the '+' (Plus) key on the numerical keypad to duplicate the row of polygons. With the pick tool, move the new row of polygons to where you would like to have them in relation to the first row of polygons. Now select both rows of polygons and duplicate, again. Keep this up until you have a layout of "Fill" Polygons as large or (preferably) lager than the target polygon that you wish to fill. Once you have this, select all the polygons and then Click on Arrange->Group or hit Ctrl+G.
To place the "fill" polygons inside the target object/polygon, select the "fill" polygons and then Click on Arrange->Power Clip->Place inside container. Once this is done, if you need to adjust any "fill" polygon, inside the target polygon, you can go Arrange->Power Clip->Edit Contest (and Finsh Edit Contents) to show all the fill polygons and allow you to move/delete as you wish.
Hope this simple method works for you.