Yes, they are both okay, but 1 hour is singular, not plural, so it should be: I have studied for 1 hour. (or) I have been studying for 1 hour.

两个都可以，就是意思不一样，i have studied for 1 hour意思是我已经学了1小时了（现在已经休息了，没在学习） i have been studying for 1 hour意思我已经学了1小时（现在还在学）

Both are correct, but when you use past simple it means that the action has already finished and when you use the past continuous meand that the action continues in the present. I''ve studied for 1 hour --> I have already finished studying. I've been studying for one hour --> I started studying one hour ago, but I'm still studying

You can't say 'I have studied for one hour' To say how long use the progressive tense e.g. 'I have been studying for an hour'. To say how many/often/much use the simple tense e.g. 'I have studied English at lots of schools' 'I have studied too much today'

Both, but *Hour