[ubuntu] Ruing Ubuntu 16.04 from USB stick, booting is Ok, but not able to detect WiFi

Just bought a new HP Pro laptop with Microsoft Window preloaded and Wifi works well after the computer is booted from Microsoft Window. I want to lea Linux, but I do not want to erase Microsoft Window from my computer. As I have very little knowledge in computer, I want to be safe to run Ubuntu only from a USB stick without having to install it on my Laptop hard disk. After I downloaded Ubuntu 16.04 LTS on a USB stick, I am able to boot the computer from Ubuntu on the USB stick. However, I am not able to establish Wifi inteet coection after multiple try, although the same laptop computer is able to automatically coect to Wifi after it is booted from Microsoft Window. I am very new to this (not a computer person) and I am completely lost! Please advise what to do to establish WIFI after booting from Ubuntu. Thanks.