Exactly which Magix program are you using? There is quite a range from fairly simply to pro quality. Indicating you program name and version number make it much easier to provide help.
My usual first comment is to 'just dive in and experiment', as Magix editors are 'non-destructive' meaning if you cut a video in two and remove half of it you haven't done anything to the original clip stored on your system -- usually your hard drive. And of course there is an 'Undo' option to back out of most situations.
Next is 'Help' itself!
Common to most Windows programs is an in-built help system with search facilities. Click on the 'Help' item on the top menu bar to see your options. Of course you have to know what to look for. :-) I started with 'GIF' and found that that file type is supported -- this in Movie Edit Pro 2016 but most likely in all other programs. There is also an option to export as a GIF, but there are lots of other file formats that can be imported or exported. The Magix editor does the conversion. Next I searched for 'blend'...
Here things get a bit more complicated as you get introduced to the rather special language of video editing -- transitions, fades, and dissolves rather then blend.
Download from the internet? A typical option is a right click on an object and pick 'Save as...' from the menu.
Note also that the 'Help' menu also has an option to watch an introductory video online, and last but not least you can search the site here for tutorials:
Many will be rather specific and perhaps advanced for now, but you're sure to pick up ideas.
A right click on a web page should lead to a menu with a 'Save as...' option, but depending on the page details this may be only an option to save the entire page as a html file, rather than save the video as GIF or mpeg. This shot is from a Facebook page:
If your MEP 2015 is the 'Plus' or 'Premium' version you have a screen capture option within the editor (and lots of other extras!):
A web search for "screen capture" will get you no end of ads for programs to do the job; many of them are free.
Finally, at least for the moment, have you had a look at any of the tutorials? beside the ones on the Q&A and Forum pages, there are several available direct from the Magix MEP pages:
Unfortunately, your first post has nothing to do with the thread you have placed it in! Please do not hijack another user's thread with a post that has nothing to do with the original question. Also, did you notice the thread was last posted to nearly five years ago?
Please start a new thread in the Video Products area of the forum, making sure to select Movie Edit Pro as your program. When you do this, please also read this post and give us ALL the information requested there.