How can i update software

Go to Settings/General/Software Update.

i just had a problem with the last update my screen would freeze and say verifying update and did that for days i had to download itunes on my computer and manually reset it if you dont have that problem then you can just go to genral in settings and find software update you have to have at least 20% and connected to a charger and have wifi i believe

Update your iPhone: https://support.apple.com/en-us/HT204204