General principle is that you set up the filter to pull water in, through the filter media (I use large sponges and polyfilter) and out the outlet. I don't know anything about that specific filter I'm afraid.
You mentioned about carbon - as I understand it with carbon you need to be replenishing it regularly...every 3 or 4 weeks if memory serves, but I don't run it myself so not sure. I do not that if you do not replenish the activated Carbon it is pretty useless, and some people consider old Carbon media left in a tank to contribute to fish disease. Carbon is also used after treating with medicines to extract any traces left after the course of treatment.
I'm thinking of getting a new filter. I was wondering what is a good filter to get ? Any suggestions or anything would be helpful thanks in advance if anyone can helptank size 4'x18"x29" they said it was 110 gallon
You have a ton of options and like folks have already said, read up and avoid the common mistakes (that alot of us have made) and you'll enjoy it a bunch.
As far as filter, I's personally go for an XP 3 or 4 AND an AC110. I've never used them, but eheims are also highly recommended.
I will chime in on the Rena XP3. I have one on a different shaped tank of about the same volume and its going strong after 2 years. My personal favorite way to set up a big tank is to think of it as lots of small tanks. In a small tank I might put 2 or 3 platies so in the bigger one I'll put 7 or 8. In a small tank I would stretch to put 4 cories in it so they can have some company, in the larger tank make it 6 or 8 and you don't need to stretch to get there. The general idea is that you have plenty of room for lots of variety of medium to small fish and can have a very active tank with lots of movement. Someone else has already suggested a very few very large fish but I always find a tank of any size with only 2 or 3 fish big enough to fill a large tank as rather dull by comparison.