1st part time job

i had work out my 1st part time job in last week, it was on my thursday to friday. at the begining it was quite hard for me to manage the section in my responsible for the first and second day. however, on the third day i start to cooked with all the section in my work place because on the second day i am in charge for the whole section and i need to do it all by myself. since then, everyday after work i feel a bit tired, because i need to stand for about 7 to 8 hours per days. anyways, what to do? i do not have money what. XP