Go to your breaker and check to see how many outlets that 1 breaker supports. If you have a 20 amp breaker and that breaker supports a couple of outlets, you have to consider how much that breaker is supporting and it's not 20 amps per outlet. Turn on the lights and plug in a couple of appliances into the outlets and turn the breaker off to see which outlets go out, then add up all of the amps...
Also, you can always change the breaker to support more amps but it's not as simple as changing a 20 amp breaker with a 30 or 40 amp. What you have to pay attention to is the wire that goes to that breaker. If you have a 40 amp breaker but the wire going to that breaker is max 20, what will happen is the breaker won't trip when you overload it but the wire can't support it. What ends up happening is the wire heats up and start to burn....that's why houses burn down...
When I started mine, I didn't know too much about this stuff and the idiot changed my 20 amp breaker with a 40 amp breaker but didn't know that the wire could only handle 20 amps....On that 1 line, I had (3) 600's (1) 400 watt light and about 14 amps of equipment....Because I didn't trust the work, I had an electrician friend check it out who broke it all down for me and separated all the lines into 3 separate lines....The wire going to my box had heated up and started to burn....I was lucky, another week or 2 and no more house....