At the top of the screen it will say JP and EN. Click on that to switch the site to English. its translated from Japanese so it isn't perfect but should be enough for you to navigate around the site. It's about 999yen a month which translates to just under $9.99 so for some its cheaper than the WWE Network even if by a few cents. If you subscribe make sure you do it on the first of the month. They bill you on the first no matter when you sign up.

Normally when a show is live it'll show on the top highlighted in yellow. You can always go back and watch older shows as well, some of the big shows have English commentary.

Here is a spreadsheet of recommended matches in order of year, you'll see some WWE talent on these as well. Good way to see some amazing pro wrestling matches that you may have missed.
https://docs.google.com/spreadsheets/d/1ZsZCBTpKjHzdbCpKZ1No1KAdpmOd2OcgSMfC1-oa7pI/edit#gid=0