I purchased my 05 Altima 2.5 about 6 months ago. Not long after I began experiencing a very rough idle while being stopped at a light or stop sign. I could shift into neutral while sitting there and the idle was smooth. I was told to replace camshaft sensor and did. That fixed one issue but the idle issue remained. The car then threw a code for cylinder 4 misfire. Then the check engine light went off, then back on. Had code checked again. Was told cylinder 3 mis fire and code for catalytic converter. After a suggestion from a friend to replace coils, I went to by them today. The guy at auto zone suggested I wait and gave me some cleaner to try. When checking the codes today I was only getting codes for catalytic converter. However, the idle is still extremely rough when in drive and stopped. I'm also only getting roughly 370-380 miles per tank, which is lower than before. Any help would be greatly appreciated. I'm a single female and want to make sure I'm making the right decision.

Welcome to NICO!

The cats on that generation altima are prone to failure. The catalytic converter isn't all too cheap, but most any muffler shop can take care of a quick swap for you.
However, before that happens, head to an auto parts store and have them pull the code again. Write it (them?) down, and post it here so we can help you further before you spend some potentially unnecessary cash on the converter.

Welcome
Did you try swapping that coil pack in the cylinder that misfired say -#4 with another cylder say #1 to see if you can pull the same misfire code in the #1 cylinder,just to try to eliminate the question of having a faulty coil pack?