I am guessing that when it refers to going out with friends, you will be drinking and since you want to do not want to skip (or skimp in this case which is wrong) a meal, you will be drunk at McDonald's. "You'd rather not" and "you don't want to" are basically the same, but "you'd rather not" is the more advanced way of saying it.

Reasons for Being Happy (IELTS writing task 1)

The following pie charts summarise the factors why under and over 30 people feel happy.

Independently on the age, the charts feature 30% people that are mainly satisfied by their success at work. On the second place, practicing hobbies is another source of glee for either of the categories, representing respectively 22% and 24%. Next, 18% of under – 30 people take care of having a good appearance, whereas about the same percentage of the elder group feels glad by financial security. With a proportion of 15%, the younger group enjoys traveling, while the over – 30 people prefer being with family. Other factors, that are not explicitly mentioned, constitute 14% and 10%, respectively for the younger and the older group.

In conclusion, achievement at work and hobbies persist as the main sources of glee for any age. By contrary, appearance and traveling are factors that only appeal to young people, as the older ones are more interested in supporting the family financially and spending time with it.

yellow highlight = correctly spelled words 

green highlight = added words

blue highlight = replaced words

red highlight = delete it

your English is great, keep up the hard work!