Thoughts on organizing code for multiple mysql queries in php scripts

I have a web application where I connect with a MySQL database using PDO and in some scripts there are a lot of queries one after the other which don't necessarily concern the same tables. i.e I will execute a SELECT statement in one, and then depending on some values I will UPDATE another and finally go and DELETE from another one.

The thing is I only recently learned PHP and MySQL and because I wasn't sure and wanted to be careful and to find easily any problems (and a little because I am a little ocd and anal about silly things like uniformity and coding style) in every query I used the following format

try {
    $statement = "
        UPDATE/SELECT   ...
        FROM/SET    ...
        WHERE   ...";
    $query = $dbcnx->prepare($statement);
    $flag = $query->execute();
}
catch (PDOException $e) {
    $errorMsg = "...";
    error_log($errorMsg,3,'../../xxx.log');
    $response = ...;
    $dbcnx->null;
    return $response;
}
$result = $query->fetch/fetchAll/fetcColumn...

so I could find where any problem would occur (try/catch) and to be safe against injections and invalid characters (prepare) (I had some personal checks but I am pretty sure that a function specifically made for would be better).

When I had one or two queries it was fine but after the code grew it became a little too much code for little action/substance (like 16 lines for one query...)

So I would like some advise. How do I make my code more manageable? Is there some fundamental error in my logic on structure (the way I wrote it)? Is there some rule for using try/catch? Is it more for developing and debugging and afterwards you can remove some blocks of it? Is prepare enough for rudimentary security on queries?

I was thinking of making a function of just this block of code and calling it with the statement as a parameter. So I would just 'type' the query in the main body and then call the function where it would be prepared, executed and then return the result. Of course then I would always use fetchAll and would return an associative array but I think as long the datasets are small the memory usage would be fine (in any case in nowadays systems it should take A LOT to notice a difference, I think)...

EDIT: I was told about abstraction layer, which I admit I am a little fuzzy about. Basically it is a class which is instantiated every time the script/function runs and wrap the functions used repeatedly (along with the checking I do) inside it?