At the very first, research what UI and UX design is
UX design is all about the overall feel of the experience, while UI design is all about how the product’s interfaces look and function. UX design is all about identifying and solving user problems UI design is all about creating intuitive, aesthetically-pleasing interactive interfaces.
Learn some basic principles of UI designs
Before jumping into UI/UX design you need to learn some design principles. Learn the psychologial aspects of design: why it can look good and why it can bad. Master the basics of visual design as ( designing buttons, typography, white space, drop shadow, working with color combinations gradients, different kinds of grids layouts etc)
Some basic principles you should know;
Color, Grid System, Typography, Balance, Contrast
Understand the UX design process
UX design process is an iterative method that helps you continuously improve and polish your designs. In the process, you go through different stages repeatedly while evaluating your designs on each stage.
The design process involves the following six stages;
Understand, Research, Sketch, Design, Implement, Evaluate
Learn the design tools
There are lots of design tools out there, but you don’t need to know all of them.
Here the list of software that you should give it a try:
Adobe Xd  – For interface design & prototyping
Figma – For interface design & collaboration
Sketch – For interface design
Familiar with design rules for each platform
IOS, Android, Windows, macOS platforms have their own design rules and preferences in mobile application design the resolution of each model, status bar, height, navigation bar, icon size, font, color have their rules.
Here the official UI design guidelines by
Apple Developer: https://developer.apple.com/design/human-interface-guidelines
Material Design: https://material.io/design/guidelines-overview
Read design books and blogs everyday
Here the list of some books and blogs
Books
The design of everyday things
The basics of user experience design
UX design process best practices
Elegant web UI design techniques
UX design for startups
Blogs
Uxpin
Ux Collective
Ux Planet
Careerfoundry
XD Ideas
Practice design and take inspirations from other people’s works
Here the list of popular websites for inspiration:
Behance
Dribbble
Muzli
Awwwards
Pinterest
Bonus Tips
Best YouTube channels to learn UI/UX design
Here the list of popular YouTube channels:
The Futur
Mizko
Flux
Graphics Guruji
Design Piolet
Pierluigi
Giglio