Hi Ball-Banger
Your question is ABSOLUTLY no newbie-question- ( hate the word newbie anyway- this word is used too often for negative thoughts

)
As you wrote, you started recently to play pool-billiards. Welcome to the family. It is a great sport- i think i ve choosen this beautiful sport, because it s absolutley your own faul-no matter what s going wrong on the wide green table.
The point you shown up about concentration is very good and asked not only by new players- also many (really many

) players getting crazy about this-especially if they begun to spend time with playing straight-pool (also my greatest love)- and it s all about training like in any other discipline of pool (or any other sport if u want).
I will try now to show you what i usualy try to transport to everyone who s training with me, asking me or getting lessons...here we go
First i wanna start with just a few (really a bit, lol) psychological/mental aspects, which are god-given by nature. Our brain is workin with visul inputs, with nothing else!
So if you re starting your inning- the first thing you do is to go to the table (wow!). Then you try to analyze what you see. Decided for a ball to shoot it into a pocket- and usualy you looking for the next position. Here is the first very big point i try to recommend and give ppl with em on their long way while playing pool-
-you checked how to pocket the ball – Yes
-you checked where you wanna have the position with your best friend (cueball^^)- Yes
-now a good player usualy starting his job- means to go down , gettin into stance, doing your test strokes- deciding if it feels good while aiming at the object-ball- brain says :OKAY buddy- so you shoot it, gettin position and ready!
Ok, that would be the case everyone loves- but the difficult things in this game happens to everyone- what about bad ideas?- while you are lookin for example to get your wanted position- if you re thinkin about what could happen in worst case? THATS a very bad thing! How i shortly wrote before- your brain is workin just with visual pictures- and if you have now this negative visual picture in your head, you have a problem- IT IS THERE!. So go away from the table- and start your whole pre-shot-routine again If you pocket the object ball how you want, and hit the cueball how you want- you ll GET THE POSITION-Basta!. Let there be no room for negative things.
Now the heaviest thing and easiest at the same time: Like the other guys told: You can t keep your concentration at a top level for a whole billiard-game! You can talk tales , the story of your life, you can have a look at the beautiful girls passing your table- all while you re getting your impressions, positions and ideas during your pre-shot routine. There is only one important time- and this is when you get down to shoot it! There are just these important 15-25 seconds whend you re down in your stroke where your concentration have to be in work. Try this in training while playin Equal Offense or also while training with guys, or special drills. Talk with yourself or with your friends- think about washing at home.....until you get down to your stroke! When you started to stroke, and begun your test-strokes, this is the Point of No-Return- you re doin test-strokes, brain says:“ok buddy, that s it“ - shoot it, ready.
Ok Ball-Banger- this article could have been a bit longer- because it s a complexe theme to talk about. And of course i talked about a person, who knows what to do for getting position (technical things, knowledgement etc). I just tried to show you- that noone is able to keep his concentration on a top lvl for hours- and there is no need in billiard ( or sport anyway). Just if you re going down to your stroke AFTER you got all your informations you need to do your shot successfully- then you need to concentrate for these 15-25 seconds. It s a long way to learn it- but it s worth
And further it will keep you away from those people who are searching for excuses all the time- i bet you know those guys who have ALWAYS an excuse for everything. But why? All nonsense- It s your table! Noone could disturb you! In the case somethin s wrong, get off the table and start your routine new! As long noone steals your cue or balls all is good!
Just 15-25 seconds of concentration you will need to the top

(next to your daily drills-patterns of course my friend

).
And my biggest advice for your whole pool-life: if somethin happens(scratching, don t pocketing etc) get your chalk, KEEP SMILING and sit down and enjoy watching your opponent
I hope i was able to transport what i wanted to explain you,
have fun all the time while playin pool my friend,
lg from germany,
Ingo