There are lots of reasons not to get comments or likes, and the reverse is also true that there are lots of objectively bad (from even a basic writing pov) that are popular. Popular and good quality don't always line up. Nor does engagement. Daytime soaps are not a beacon of amazing story telling and are often badly acted, inconsistently written and cliche as hell, but are popular and easy to watch. So don't get too hung up on engagement = quality, especially early on. It's very common not to get engagement early on.
Also, just first novels tend to suck. It's a fact of life, basically everyone's first novel/project will be lacking and should be treated more as a learning process.
As for how to know, it's very hard to. Find a particularly brutally honest friend who knows what they're talking about, hire an editor, or even make a post here asking for advice/critique. A lot of people here in the community will give some basic advice and thoughts and critique if you ask for it. Having taken a quick look myself, the first immediate thing that hits me is your summary. I'd suggest a rewrite of your summary, it tell me nothing. A good, simple, example is template is:
This is Main Character. The goal is Goal because Reason. But in their way is Problem. To get around Problem they have Plan but will it work?
You need to give the any potential readers a clear idea what the actual plot is. Your summary is key to getting readers just to your novel and giving them an idea if its for them. If you want proper critique beyond that, like I said, just make a post asking for feedback and people will probably give you more in depth stuff.