You can hit a search on google !!
The other way is if you have some basic knowledge of HTML you can customize the minima template which is easy to customize.
First thing you would have to do is download an FTP. This is used to upload files to web servers.secondly you would require a web hosting to host these files.
Under the Edit mode of your blog, go to the "Layout" tab and then click the "Page Elements" tab. On that page, click on "Add a Gadget." Then, select "Video Bar."