How can I rank my website's homepage?

Its your back link profile I do believe

Here go run your web site thru Ahrefs free tool.

https://ahrefs.com/backlink-checker

A heads up... your backlink profile is not good.  Clean it up.

I agree your backlink profile needs some serious work. That does not mean spamming forums, blogs etc with your URL. We are talking about proper links to your site. 

However, there are still some improvements you can do to your site. Your images for example are huge. 2.5mb of images on your home page. 3 x title tags, your h1 tag is an image. Your liberal use of the H2 tag weakens the correct H2 tags, for example, why is Login to my account, Recover password H2 tags ?

The speed of a site loading is a ranking factor, yours took 5.33 seconds to load, this is too long and mostly due to the images I suspect. 

Although these by themselves won't get you to where you want to be it would be something under your control that could be fixed. 

I believe, by creating high-quality content, reaching out to relevant websites, and focusing on natural backlinks, you can improve your website's ranking and drive more traffic to your site. Moreover, using automatic link-building software can be beneficial for saving time and increasing scalability. I'm using Postifluence which helps to discover high-quality blogs in any niche you target and its automatic system reaches out to bloggers through Email and SMS. It's quite helpful.