hi shivv420!
firsth study money management and lot usage!
if you search on youtube there are several videos ... then you have to study some trading techniques ... there are lots of them for every style and time available!
Basically consider the ratio every $ 1000 on the account -> 0.01 opening lots. Then depending on the type of trading and how long you want to keep the trade open, there can be many variations on the size ...