Pricing projects

I am new to working with ThreeJS in a professional context and web development in general. I have a vague understanding of how to price websites for front-end that may incorporate react for smaller businesses and projects. With ThreeJS I am having difficulty pinpointing how to price a project outside of hourly wages. Even with hourly wages I have some difficulty because every project is different and requires some amount of research. I am unsure how to price based on the amount of time dedicated to research. This brings me to wanting to price projects not by hourly wage but as a whole or by milestones. Just I am too inexperienced to do this yet.

Could someone give me some guidance on how they go about pricing projects? Out of curiosity how much would a site like cost? The Greta site is out of my skill set but it will help me understand this.