Slider - slow that down please. Don’t care for the background color of the sticky menu, About Us section, This does reflect an older style of design, look at examples on Themeforest. One example of a more modern style. Fill full width of page with image on left and Heading, text, etc. on right. No margins. Don’t round the edges on the image. Make it a rectangle. Lots of examples to look at. Icons under Services section too big. Use different background color behind each section, even if it’s as simple as white, followed by light grey. Use a different sans-serif font. I like the Some Facts section. Main text too small on different parts of the page.
I didn’t look at the site on other devices, but can tell you what I saw in my Chrome emulator extension… Iphone, Testimonials text not fitting on background properly. First slider image. If you’re going to put the text over the slider on the left, then you should try flipping the image behind that horizontally, so you can see the main subject of the image. Meaning, so the man on the computer can be seen on the right. Ipad emulator view, nav bar goes to second line. Nav bar not lined up properly with the logo. One option is to use hamburger menu on Ipad, another is to change padding or margin of logo and nav items, so everything fits properly. Good luck!!!
Please do not ask people to check your code. The main issue of your template is the design anyway, you should focus on that first. Just check some recently approved bestsellers here on ThemeForest if you need inspiration.