Hm .. let me see.
I'll make a quick one and comment on what I've done. Remember that this is a 5 minute work though, and you should put a lot more effort into images to make them end up looking like the ones you listed
So first of all, open up Gimp and make a new image (File > New) with your desired size. I took 200x150 pixels in my example.
After that, go to "File > Open as Layer" and select your image (the one that shall become the logo). Your Gimp window should look a bit like this (mine is in German and a bit customized, so don't mind the little differences):

Now that this is done, your background image might be way too big for the small image you want it to be in the end. You can solve that by resizing the image you just opened. On the layers dialog, click on the layer of the image you opened. Then, on the main window, go to "Layer > Scale Layer" and scale it to a size you're fine with. If it's displaced, for example if you can only see the head of 1 person instead of the whole body, you can also use the Move Tool (The small icon with the 4 arrows in your toolbox) to move the image around.
I scaled my image down by 50% and moved it around a bit to get a nice scene of my grass shot into focus:

The next thing you wanna do is create a rectangle selection around the center of your image. Do this by selecting the rectangle select tool (
Link if you don't know where to find it) and then making a selection click-and-drag style

. You should end up with something like this:

Now, to make the selection rounded, go to the tool options. They should be floating around somewhere. If they don't, a small click on "Windows > Dockable Dialogs > Tool Options" should reveal it again. As long as you selected the rectangle selection tool you should be able to select an option called "Rounded Corners". Check the box next to it and move the appearing radius-slider around until you are satisfied with your result:

Now, just as a preparation step, add an alpha channel to your image and hide your background layer. You hide layers by clicking on the small eye-icon next to the layer's name in the layers dialog, making it disappear (THE BACKGROUND LAYER, NOT YOUR IMAGE LAYER). Alpha channels are added by rightclicking on a layer and selecting "Add Alpha Channel" (TO YOUR IMAGE LAYER)

Now just follow these steps:
Select > Invert
Select > Cut
This should leave you with the following result:

Now, create a new layer with default settings by clicking on "Layer > Add new Layer". Leave the settings and hit okay.
The small text rectangle is created by the same steps we used earlier:
- Select the rectangle selection tool
- Click and drag around the bottom half of your image
You should end up with something like this:

It's now time to choose your color!!

Click on the little black rectangle you see at the color selection icon (see image below) and select a new color in the window that appears. I used a random orange tone:

When you finished selecting your color, drag and drop the little color rectangle you clicked on in the last step (which should have turned your color now) and drag it into your (still active) selection. It should get filled with your color now:

The rest is just some decoration: Get the small holes into the text rectangle by selecting the Round Selection Tool (see image) and click-dragging a small hole. Then go to "Edit > Cut" and you've got a hole in your rectangle:

Repeat this on the other side and finally add some text with the text tool:

Finally, save your image as "YOURNAME.png", the _.PNG is important to keep the background transparent, a _.JPG would fill it up with black or white.
My example image ended up like this:

Again, I did this in 5 minutes, so your result will end up WAY better if you take your time. Select good images, ,match the colors and text and you should be fine

Hope this helped.
Post your results or your questions if you have any.
Arzo