First paragraph is mostly just me blabbing, sorry I am a ranter. Thank you in advance for any advice anyone has to give.

First I would like to start by saying, I don't know to much about cars at all. In fact even though I am 28 years old I have just gotten my drivers license. I had never really liked cars much, or that was true until I saw my first old diesel benz. They are so damn classy and beautiful, fell in love. That said I apologise if I use the wrong words to describe things here, I'm doing my best as a total novice.

I decided the place to start was reading everything I could about all sorts of problems other people have had with their 240d's I have also ordered the Haynes Manual and 1976-1985 Mercedes Benz 123 W123 Chassis Shop Workshop Service Repair Manual as well as chiton, 82 benz 240d manual. I really was not sure what one was best so I just got everything. Those should all be here in a few days, are there any other / better manuals to get? So the car is not in great condition, I can drive it. IT shakes a lot and I have located and found out that the engine mounts are total destroyed. Is it safe to drive the car like this? I have ordered new parts for that all ready.

Next, OIL CHANGING. So, is one kind of oil better than another? I'm in houston texas so I know I don't need to worry about it being cold. Also, I have read in a few places you want to change the oil hot? I'm a little scared to do this. I have only ever watched someone change the oil on a gas car once and though I have watched a view youtube videos and read some literature I know that when I saw someone change the oil on a gas car it got on them. I'm a bit nervous about melting off my flesh, any pro tips? I did see one video where they pumped the oil out vs draining it, is this as good? It seems like you would get more sediment out by draining, tho maybe not?

So I was able to locate one part of the car that was clearly broken. And I figure after changing the oil, which just seems like a good idea and the engine mounts I should get this bit repaired :

So I am not 100% sure but I think this might be a check valve? So here is the thing, this is an old car its not like I can go to generic auto part store and just get pieces right? Where are the best places to get parts from? Other than used or rebuilt pieces from the same model are there brands to avoid, or to go after? I did notice that when I was checking the cost of tie rods that the range was anywhere from $10.00 to $23.00. I need to get those to, but again I'm really worried I might buy sub quality parts If I just get the cheapest ones, but also I don't want to just buy the most expensive if its not actually better. Suggestions?

So Other than changing all the filters in everything, changing all the fluids, getting the car aligned, fixing anything bad with the suspension (other than tie rods I'm not sure what else to look at yet) remounting the engine and repairing anything I find that is obviously broken such as the picture above are there any general maintenance and care tips anyone has? Or things I should look at on the car that a person with no experience may over look?

thanks for any help / tips / suggestions anyone has to offer!