Change paragraph font and video not playing in mobile mode

Hello I am using the free version, but hope its OK to request support for these issues. 1. I would like to change the paragraph font to match the heading font. Is that possible? 2. Also for my website, the banner video is not playing in mobile mode, what can I do here? 3. Finally, I would like to reduce the size of the banner, I found the points where to edit in the CSS but its quite a lot for all platforms, is there an easy way? Link to website: http://130.159.17.33/xiao/ Many thanks in advance! Marvin