We don’t see the login form http://prntscr.com/sovkhi
To translate that texts go to Loco Translate > Plugins > XStore core plugin > edit your translation or create it if you have not created it yet and translate the mentioned strings.
If your site worked fine but suddenly, without any changes from the theme side, it became slow then contact your hosting provider about this. All the theme options that could help you to speed up your site you can find in Theme Options > Speed Optimization. Also, read the main tips for the site optimization https://xstore.helpscoutdocs.com/article/100-how-to-speed-up-my-website
