I need an enter/loading page on top of my home page (Wordpress)

I need an enter page in front of the home page with an enter button.

When you click the enter button I want it to say 'loading' and show my animation (I have .mp4 .mov and .JSON available) and for it to animate in like this:

http://preview.themeforest.net/item/the-wavo-ajax-creative-wordpress-theme/full_screen_preview/24885524?_ga=2.84871129.1122780268.1620574894-83024560.1607446799

If you can imagine my animation would replace the 'W' on the above link.

Then the home page is revealed behind... like in the above link.

How quickly could you do this? Thanks