Please help me with my Samsung phone

[OccasionallyFlagging]

I have just bought a Galaxy A42 5G phone but I don't know how to use smart phones yet! My current phone is a flip phone but I have decided I mustn't let technology pass me by.

It keeps turning itself after a couple of seconds it's left unattended, and needs a login code to open again. Every flipping time. I've logged in about 50 times already today. Is there a way of telling it to wait longer before it turns off?

Also, it comes with some random moving blobs on the entry screen as a wallpaper background - is it possible to change that so I can choose a nice picture instead?

Please help!

Does this help at all @OccasionallyFlagging - www.samsung.com/au/support/mobile-devices/adjust-screen-timeout/

And this - www.samsung.com/uk/support/mobile-devices/how-do-i-change-the-wallpaper-on-my-samsung-galaxy-smartphone/ - for the wallpaper/screensaver?

Can you access You Tube on a different device? Step by step guidence in your own time. I use it to explain everything!

Settings
Sleep mode/time out mode

You also change the wallpaper in display settings

Yes! Brilliant, thank you!