there are some signal providers who provide signals to be copied in metatrader...
some provide signals with a fixed lot size of 0.01
how can i edit the lot size to be 0.1 from the signals received
You cannot edit the copy ratio between the signal you are copying and your account, it is calculated automatically by MQL5 signal copying system.
There are some products in the market, that can do that but its highly unadvisable, because you will mess with the money management and the trading plan the signal provider has in mind.
In other words you will end up loosing much more, if things go wrong and always things go wrong!