Your panel ought to have a main breaker which ususally has the amperage rating on the handle. Sometimes not though.
C9 - 7 watts per bulb - 25 light string = 1.5 amps
Mini lights - 100 light string = .51 amps
You have 23 sets of C9's = 36 amps. I factor in continuous use which is 1.25 x the amperage so the C9's are 36 x 1.25 = 45amps.
20 sets of 100 count minis - 10.2A x 1.25 = 12.75
You're looking at 57.75 amps, not counting the wire frames and any additional.
If your service happens to be a 200 amp service, you're probably in good shape, even to add many more and a 100A subpanel.
If your service is 100A you're probably close to the limit depending on theings like how much of your appliances are electric - water heater, heating, cooking. If all of that is gas, then you still might have a little room.
The best bet would be a 200 amp main service with a 100 amp sub-panel.
I just noticed that you said you had two panels and about 30 circuits, so my guess is that you have a 200 amp service. Best to let a local electrician check it out though.
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