newbie question regarding p trap replacement

I barely brushed against the bottom of the p-trap underneath the sink this weekend and it fell into little pieces. I went and bought another one and was replacing it when I realized the pipe connecting the trap to the wall pipe was cracked too. In trying to remove it, it too has become a million little pieces.

Now I'm scared to do anything because I know if I screw that pipe in the wall up, I'll have to pay somebody who knows what they're doing to fix it.

What's the best way to get this thing out? It seems stuck in there with some glue-like substance (plumber's putty?). As far as I can tell, they're not threaded together (I see the wall pipe has threading on the outside) but I'm not sure. Just grab it with pliers and pull?

And if I do get it out, do I seal the wall pipe and the new pipe with putty, or something else? This connection was wrapped in a ton of electrical tape, so I'm suspicious this wasn't done correctly to begin with.

TIA!

Like it or not, you have to open the wall to access the drain line where the P trap tail piece is connected. The way they connect is normally with an adapter that has a male thread on the outside that allows a slip connection with the tail piece and is connected to the drain by one of about 4 possible ways depending on the material the drain is made from. If the drain is copper, the adapter is soldered, if it is ABS or PVC plastic, it is solvent welded, if it is galvanized pipe, it is screwed in. It the drain is cast iron, it is leaded. Until you open the wall you won't know what you are facing. Either of the plastics might be a DIY project. Anything else will certainly require a professional.

The dirty arm is gonna have a santee that will crumble too. Nature of the beast. Gonna need some banded couplings.

trap

You are correct that it was not done properly to begin with. That is a steel pipe coming from the wall and there is no way the trap could have been properly connected to it without some type of adapter which you do not have. No way to tell what they used to join it, but there is also no way to redo it properly without removing that piece of pipe.