Hi guys

I am new to this forum and website, someone on eBay recommended I join up after I asked him some questions about coins he was selling  ...so I thought I would ask here before making a post with a ton of pictures if it's ok to do so and what is the expected etiquette here?

I was given a bunch of old Australian pennies and half pennies recently.....about half of them are the ones with the kangaroo which are not as old ...but the other half are the older style which look way cooler in my opinion anyways ....probably 100 or so and I was hoping to post pictures of them up here to see if any of them have any value or are rare coins ...I know at least one is an I think 1919 double dot error, something to do with only a limited amount was struck as they had only one of the reverse die ...as more and more coins were struck with this one die a part of the coin got fainter and fainter making those coins errors... something like that  ...I'm not sure about the others if they have any value are rare or very common. 

I have a relatively large coin collection ..inherited a bunch of them  from my father ..have collected my own over the years when I travelled the world  and keep getting given coins .. people find out you collect coins and coins often end up becoming a popular Xmas or bday gift haha

 I have a good few coins from the USA like Morgan dollars ..double eagles ..holographic I'm not sure what it is haha
Have some international coins like a Hungarian shachta which dates back to the dinosaurs almost hahah and Denar along with a bunch of old Roman coins which I doubt are worth much...
Bahamian proof sets ..old casino tokens....
Have an interesting coin ' pin type thing that I got from a geocache a while back that is a USA geographic survey coin ...kinda interesting not sure what it is but it looks neat....

Have some metal detecting finds which look like old English coins...

Also many Aussie coins I am not that familiar with so could use some help.. ..I have some modern noodled coins like the fancy 2 dollars with the rings in the center of all different varieties ..
I also have one of the millennial 2000 coins with the incuse flag I believe it is anyways haha
A round 50 cent from I think 1966 ..somewhere around then I believe 
An 1896 gold half sovereign which was dug up in Nowra with a metal detector 

I also have quite a large black Opal collection ..I took a gamble bought around 6k worth of rough from lightning ridge  that was very promising and had a professional cut them all ...but I'm sure valuing that is for a site about opals not coins haha
I just really dig  to collecting rare stuff!

Anyways I would love some help in grading and valuing all these coins so I can slowly catalogue my collection ...
Is that something that's done on this website ?
 I would of felt obnoxious to just come here and post a bunch of pictures and questions right after joining so I thought I would ask all of you first ?
 Or should I participate for awhile here on the website in coin chat before I ask such questions ? I'm trying to be respectful of everyone and  of how things are done here

Cheers and thanks for the advice in advance 
Rob