You can use leverage to open a Perpetual Contract position, which means you only need to put some margin to start.
For example, if you would like to open a position of 1,000USDT, the leverage is 100x, the initial margin =1,000USDT/100x=10 USDT.
To calculate the initial margin required for USDT Contracts, multiply the order value with the initial margin rate. The initial margin rate depends on the leverage used.
Initial Margin = Contract size x contract value x Entry Price / Leverage
Example: Trader place a long entry of 1,000 contracts at USDT 10,000 with 50x leverage. Initial Margin=(1,000x0.0001x10,000)/50 =20 USDT
Maintenance Margin is the minimum amount required to continue holding a position from getting liquidated. For example, if you hold a position of 1000 USDT and the Maintenance Margin rate is 0.5%, then you should keep 1000USDT*0.5%=5 USDT to avoid getting liquidated.