Building a simple weather app

I want to build a simple app that showcases the weather for the next week, what programming languages and APIs would I need for this? I'm a beginner to coding and have experience in html css and JavaScript. Also how long do you think this would take?<br><br>I've been coding for 2 years and I've never actually finished anything due to no idea how to complete it / scaling up too much so by the time the project gets to that size I'm completely lost.