Hi kior and welcome to the forum.
There's a couple of important yet perhaps seemingly contradictory pointers here.
As soon as you venture down the road of learning and using 16th note strumming, the number of possible strumming patterns opens up to virtually limitless combinations.
Take just one bar and assume this repeats throught an entire song.
1 e & a 2 e & a 3 e & a 4 e & a
That is the complete set of 16ths.
Now, to create a pattern you think about NOT playing on one or more of those subdivisions. In other words, if it was written on paper, you would rub some of them out with an eraser. Which ones? How many to rub out?
Even if you just rub one out do you see how that would give 16 combinations?
Say you chose to rub two out how many combinatons now? And if you rubbed out three? Four?
The possible combinations to create a strumming pattern spiral beyond comprehension.
That is why 16th note strumming as a creative tool, when yo're not thinking but playing by feel, is so powerful. It allows for so much flexibility in play.
Now, consider that each bar was not the same. Let is assume there was a two-bar pattern. The strumming was different between bars 1 and 2. And only then did the repeats happen. So bar 1 & bar 2 = strum pattern. Bar 3 & bar 4 = a repeat. Bar 5 & bar 6 = another repeat. How many millions of combinations now?
You mention Wonderwall.
This song has a 16th note two-bar strum pattern. Not only that, there is a push so some chord changes happen before the beat. It is quite a complex pattern. Not many bother to learn or play it exactly right.
The strumming makes the song instantly recognisable.
But, an approximation to the correct strumming still makes it very recognisable if played with the correct chords and the dynamic and emphasis in the correct places.
Here is a pdf I created of the main strumming pattern. See if it helps, if you can follow it and play it. Start very, very slow.
https://www.dropbox.com/s/6ryeazgr44cl8a1/Oasis%20-%20Wonderwall%20main%20strumming%20pattern.pdf?dl=0For other songs at this level, you may have a little freedom of choiuce in strumming or you may want to match the actual record due to it being so distinctive and integral to the sound and vibe of the song.
You have to determine this yourself.
And learning good strumming and great rhythm skills gives you this freedom and flexibility.
Hope that helps.
