Notifications cannot be postponed, SMS sound, language

[cport]

Hi,

I have two little problems with this phone. I am new in the Android world, so, be patient

1) My calendar notifications cannot be repeated, regardless I click to  "remind me in 30 minutes" or other options.

2) I cannot change sounds of my SMS notifications. (But I am able to change the sound in the setting and confirm it.)

3) How can I change my native language to English?

I have Xperia X Compact, I have got Android 8.0.0 after several updates.