Lincoln Errors?!

First, .

Next, we need pics to make sure these are real.

For the brass cent, a weight and pic would help. On the second one, it is probably Struck Through Grease, and same as the third one, providing there are no hits around it.

And don't worry about the English. I was born here and mine is probably worse than yours. It was the only course in school I ever failed and I still have a lot of problems spelling.
Your kind of lucky being in a position where coins are flowing through your hands.
I would suggest you spend a little and buy a few books on coins. The Red Book by whitman Publishing would really help you out for most coins. For pennies there is a few books out on just them and you could find out more about them on https://www.coppercoins.com
The ones you mentioned so far sound like a possible grease in the system type of Mint error. Some letters and numbers don't quite make it on the coin. However, sometimes people mistake excissive wear on a coin for a Mint error so it is kind of important that you check out the type of errors and how to spot them.
If you do get those type of books, you would find out about all the possible types of errors and some not yet discovered. Keep on looking.

Well, there isn't anything to determine as "real" - what Ricardo describes is rather easy to determine.

A missing L is either a overpressure strike or a Grease Filled Die. Either way, no premium value.

Missing LIBERTY and date would be Grease Filled Die. Little premium value, up to a couple of dollars.

The brass cent is what it is - probably brass plated instead of copper plated. The weight difference would be in the hundredth of a gram, so it's negligible. Value in AU would be very little - maybe 50 cents. If it were BU, maybe a couple of dollars.

All of the coins mentioned are rather common and are minor errors if they are errors at all.