can someone give me some advice

You will have to dump your boyfriend eventually, in order to advance to the next level, but I would suggest that you complete this goal last. Complete all the other goals of you level first and as soon as you are ready to advance, dump him. Besides, at level 7 one of the goals is to find a new one, who will give you more BA.
Now, in order to raise 4000 BA, and since you dont have any money, the only way is to play the games. Otherwise, buy money at the Bank (I think that Paypal and SMS work now, but I am not sure). With enough money, you can do all the Beauty stuff daily, go to the disco, or even rent an appartment.

You can change your hair three times a day which gives you 90 BA in total for the three times, the same with make up so thats another 90 BA. Get a scrub or use the tan bed once a day which gives you 70 BA. Also got to the clinic for 60 BA. Rent an apartment, having a boyfriend helps with BA also. Play french kiss, sort your bag out, and go dancing at the club all give BA too. If you think you can win challenges try stake challenges they give BA, but not often accepted.

Renting/buying a home
Face lift
breast surgery
I think those are the highest ones

hey can someone tell me why i lost all my challenges i'm just  3 level

if you challenge bimbos with higher BA and more expensive clothes the opponent is more likely to win. but sometimes you win challenges over people that have reached higher then you. you need a bit of luck also.