How to Hold Your Ukulele 
The main part of your body used to support the ukulele is the forearm of your strumming hand. Placing it on the front of the body place pressure holding it towards yourself to keep it up. If you’re sitting down, you can also rest the bottom of the body on your thigh for a bit of help. this won’t completely keep the ukulele up so using the left holding the neck with the thumb and the joint where the first finger meets the palm. The neck of the ukulele should be slanted up.

Proper Strumming Technique
As a beginner, start by strumming with your thumb for power and your index finger for grip, this will give you more control. Place the thumb and index together with the index sticking out a bit in a crossed shape. The thumb will point to the left (nail up) and the index will point towards your nail down. The middle of the nail should be used to strum down and the tip of the finger to strum up.

Hand and Finger Posture 
Imagine there is a line along the beck highest point of the ukulele neck. As our hand travels along the neck the thumb should be positioned along that line just slightly above the middle. There should be a U shape gap from your thumb to finger, not hugging the neck. If a finger isn’t being used to play the chord do not keep them straight or hide them behind the neck. Press down on the strings with the tip pad of your fingers. This video goes more in-depth on other forms for positions like bar chords etc.

Tuning Your Ukulele
For tuning my ukulele, I use the app guitartuna. It is free on the Apple app store and comes with a ukulele option. Strumming each note one at a time, the tuner will tell you if it is too low or high. Follow along the string to find the corresponding key and twist to the right to tighten (make higher) or left to loosen (make lower) repeat the process with all four strings. Note on the bottom is left to tighten and right to loosen.