There are a few different issues that you are trying to correct here so let's go through them from easiest to hardest to fix. Some of these fixes are assuming that you are using the most up to date version of Photoshop.

1. The blown highlight in the window most likely cannot be fixed. The in camera image did not capture any information other than pure white light in that area, and Photoshop won't be able to do anything because of that.
2. The simplest way to remove the hand from your picture is to crop it out. Just press the "c" key on your keyboard to switch to the crop menu and drag the left section until the hand is all the way in the grayed out area, press enter and you're done there.
3. To remove the straw you'll need to use either the quick select tool, or the magnetic lasso. For this straw I would recommend the lasso. On the toolbar to the left, right click on the lasso icon and select the magnetic lasso. Click on the straw and drag your cursor around the outline of the straw until the area you want to remove is selected. Close the loop and just press the delete key. Photoshop will prompt you to use the content aware delete method, use that and it will do its best to fill in what it thinks should be behind the straw.
4. Emphasizing your mother and brother will be a multi-step process known as dodging and burning. There are many different ways to do this in Photoshop; I am only going to describe the method I use. Using the quick select tool, click and drag to make a selection mask over your mother and brother, doing your best to only get them in the selection. If you accidentally get too much in the selection, there is an option to deselect areas as well. Once you are satisfied with the area you have chosen, right click on the selection and select "Layer via Copy." On the right side of your screen there should be a new layer composed of just the selection that you just made. Click back into the background layer and open the levels tool. Drag the middle slider to the right to make the background darker, while leaving the layer with your mother and brother unaffected. When you are happy with your final image right click on the layer with your mother and brother and click "Merge Visible." This should be your final product and you can save the image from there.