To start trading forex, you will need to make sure that you have enough capital with you and that you do not currently need to deposit it into your trading account.
The required capital may depend on your goals and trading style, but it's generally recommended that traders don't risk more than 2% of their total account balance on any single trade. For example, if you have $1000 in your account, it's best not to risk more than $100 on any one trade.