We have been able to trace the Le Plastrier family tree back 600 years. But we can go no further because surnames did not exist much before then.
Surnames evolved and for the last few hundred years passed from father to children. On marriage girls usually take their husband surname. Since 1837 records have been kept in England which we can now see online. These can be used to trace your family name and find your ancestors. Its not easy, I don’t think the records are always correct, there may be spelling mistakes and the records might not be complete.
To get back further you need some help, the Le Plastrier family had already made some records of their own 200 years ago and these have been passed down. While branches of the family have been lost we have started finding each other again. Having an uncommon name helps. Smith or Brown would be very difficult to follow, there are too many of them.