I want to go to Xiaomeisha for the weekend, an im coming from Guangzhou, which transportation method do you suggest me to use after i get to Shnezhen metro station

If you will reach SZ Railway Station in Luohu District, it will be convenient to reach Xiaomeisha.
Get out of the station, you can walk around on the square to find bus stop of bus line 387 and then take this line to its terminal at Xiaomeisha. After get off the bus, you still need to walk several mintues to reach the beach.