new member looking for advice

Hi My name is Jonathan and I have recently bought a 2001 automatic v6 mustang, I have already performed maintenance on the vehicle but would like to improve the performance on it significantly. I am not sure where to start so if anyone has any advice I would greatly appreciate it. Progress will not be immediate because I need to be responsible with money but I will save up and get whatever quality performance parts if it is worth the upgrade. There are 135000 miles on the car so I may be interested in a motor swap if anyone has good information on the subject.