End of holiday

This is my last weekend on holiday because I start university on Monday.
This holiday hasn't been very good because I've been working, but the good thing is that I've been able to save money for travelling on summer next year.
What about you, friends? Have you had a good holiday?

Almost perfect :)

End of holiday

This is the weekend of my holiday because I will start university on Monday.
This holiday has not been very good because I have been working, but the good thing is that I have been able to save money for travelling next summer.
What about you, my friend? Have you had a good holiday?

------------

I am not sure if you are practicing to write formally or informally, but the general convention is to spell out every word.  Also, there is a difference between speaking and writing in that you would need to learn proper punctuation in the latter.

My personal style is to avoid redundancy, so I have shorten your sentences wherever I see fit, but you could have been wordier and still be correct.  This is only a matter of preference.

End of holiday

This is my last weekend on holiday because I'll start at the university on Monday.
This holiday hasn't been very good because I've been working, but the good thing is that I've been able to save money for travelling in summer next year.
What about you,friends? Have you had a good holiday?

[Good job.  I had a very relaxing holiday, thank you.]

End of holiday

This is my last weekend on holiday because I start school on monday.
This holiday hasn't been very good because I've been working, but the good thing is that I've been able to save money for travelling the  summer of next year.
What about you,friends? Have you had a good holiday?

Good work! Keep in mind that in the United States we use "vacation" instead of Holiday. You would say, "This is my last weekend of vacation because..." I know in Canada and England they use "holiday", but if you said it here the person would probably not know what your'e talking about. Keep up the good work. Ross