Door locks and interior lights out keeps blowing fuses

There is a short in that circuit. you don't need expensive tools or electrical testers, or superior auto knowledge to diagnose. Just a few fuses and hopefully a wiring diagram if needed. One fuse or more than one? you may have to use a wiring diagram to determine what all is in a shorted circuit. unplug all components in the faulty circuit. put in a good fuse. then connect one component at a time until the fuse blows. replace that component. repeat for other short circuits. if it is two separate circuits and the above diagnostics fail, look for somewhere the two circuits could unintentionally meet. like at the back of the fusebox panel or at the wiring harness. remember, corrosion could be the bridge between two circuits that should be separate.