User Interface is the particular components of a website users interact with, and User Experience is the experience and interaction users have with the website. User Interface (UI) and User Experience (UX) are two different concepts that are interconnected. So if you want to learn any one of them, the best suggestion we can give you is you learn both of them simultaneously.
User Interface deals with what the users of the website will see when they visit the site. In other words, the color used to design it, the fonts used in the information, the size of the font, the images and videos on the websites, the alignment of the entire page, etc. In short, it focuses on the visual elements that a user encounters in a website. It can also deal with screen services or more unique systems, for example- voiced-based websites.
As a designer, building a new website requires a lot of attention to the details. You have to inspect many options by going over every detail just to select your website’s primary colors. As UI deals with forming a face for your website and what people will look at when they visit your site, it plays an essential role in creating an excellent first impression.
On the other hand, User Experience deals with how and what the customers go through when visiting your website; if it is user-friendly or not, it is difficult to access or explore, etc. UX consists of the user interacting with your website by placing their order, getting information about your business, product, and services, their in-store experiences of picking up what they ordered, and also their satisfaction with their product and the service they got.
UX insights might require conducting a study to understand the encouraging and discouraging points of the website’s experience and consider making improvements that can impact a user’s experience in a good way. Sometimes while focusing on details of website designing, the fundamental principle of UX is ignored. One might suggest some crucial features of UX, such as which approach you want to follow for customer satisfaction, should be thought out initially.
Now, if you believe the looks of your website should be based on your approach, you can learn UX at first. Otherwise, if you think your website’s design should decide the approach you want to follow, you can learn UI first.