I'm not really sure on what to follow. I'm quite new in learning Japanese, so I'm starting from the basics, and I'm still in Hiragana Level 1. When I use the PC, some characters are differently written from when I use the Phone. Is this normal? What should I follow?
I guess you have different font settings on PC and Phone. Yeah, kana have fonts too, just like Roman letters have ^^ But a sample of the differences in question would help a lot, for now it is only an educated guess.
Hiragana look slightly different in different fonts, but they're all written pretty much the same.
Things like り, sometimes appears as one curved stroke and sometimes appears as two. さ、ち and き will sometimes be one piece or appear with the bottom curves separated. They're all correct and written the same way, just think of them as if you were writing lightly with a brush. Sometimes the lift of your brush as you move around a curve will cause gaps in your line, sometimes it'll lightly drag across the paper connecting the pieces.