My weekend

This weekend, I am alone at home.  I cleaned my room, then go went shoping to buy some food. I do all of the cooking myself, and I am very tired after finished these things. I miss my parents now, because they always take took care my life. I do my work well only, but now they have passed away, never to come back.  I know I must become stronger, and believe I will happy in the future.

Notes: the personal pronoun "I" is always capitalized.

Always use a space character after a comma or period character.

Very good.

My weekend

This weekend,I am alone at home.I cleaned my room,then I when shoping to buy some food,i cook for myself,i am very tired after I finished these things. i really miss my parents,because they always take care of my life,

i do my work well only

(I am not sure what you're trying to say here, I think you're trying to say: I did my work well when they were around)

but they have now passed away, they will never come back. I know i must become stronger and believe i will be happy in the future.

My weekend

This weekend I am alone at home/at home alone. After I had cleaned my room, then go I went shopping to buy some/for food; I do all the cooking myself, and am very tired after finishing/I have finished these things. I miss my parents now, because they always take took care of me/looked after me my life. I just do my work well only<em>(? what did you mean by 'only'?)</em>, but now they have passed away, and will never come back. I know i must become stronger, and believe I will happy in the future.

<em>Punctuation - commas, fullstops - are followed by a space.</em>