Not all blues is 12 bar blues!
Typically the 8 bar pattern is 1 5 4 4 1 5 then a turnaround of 1 5
If you are wondering what these numbers mean the simplest way to explain is to think of the 8 major tones in music CDEFGABC, then number them 1234 and so on…the pattern shown relates to the number of bars played using those chords corresponding with those tones.
I’m probably not explaining it very well so let me show you. If we play an 8 bar blues in A, for example, we can number the chords as A1 B2 C3 D4 E5 F6 G7 A8. So now our 8 bar blues pattern comprises 1 bar of A, followed by 1 bar of E followed by 1 bar of D and so on which we can rewrite as
A E D D A E A E
Here’s a famous example of an 8 bar – Key to The Highway – originally written and recorded by ‘William Charles Segar although Eric Clapton has pretty well made it his own, having done numerous versions including with BB King on the collaboration album ‘Riding With The King’
see also ‘What is 16 bar blues?’