It is not difficult if you really want to do. But first you should have told if you got video editing software or not? in case if you do not have one.
You can use Windows Movie Maker.
If you use windows then you should have windows movie maker pre installed on your computer. So, most of your problem is solved.
How to achieve what you want to do?
First put all videos photos audios etc in one FOLDER and give a name My videos or else.
Before I further move you should understand the video we watch on youtube or any where else is based on clips with sequence no matter just photo with commentary or video. Therefore the clips you got will do fine and even some photos.
Take a memo and write down what you want to do with clips and photos.
Then give them serial number to those clips and photos such as. When the video will start you should have shown the image of that person or video clip to introduce right. Then what is all about and decide what should be at end.
Now you have Intro
What is this all about
Finally End
Go and think what you want from your videos clip and photos to be added. If you want to give any title or add commentary write it down too.
Go to Windows Movie Maker open it browse your My Videos folder then Import all items one by one. Then drag and drop them on the time line. When you will drag and drop one video clip if you put your cursor at the edge of it you can move left or right reduce the size if you want.
In the same way you can drop photos in between video clip and audio if you have any or commentary. You can add transitions, title, you can also use different fonts and colors.
This need some practice, therefore I request please try yourself if you think you need Help file in pdf for windows movie maker or any extra help send mail with detail question to nihon94@yahoo.com
Hope this answer will give you some guide.