In the featured photo, you can see the original runic markings. Here’s a larger, more readable version. These are also known as “futhorc,” which was a derivation from the “older futhorc.” While it can all get a little complicated, here are a few basics.
Three extra letters (þ ð æ) were included along with
a b c d e f g h i l m n o p r s t u w x y
As you can see, J, Q, and V are not included. K and Z are two more not typically listed as part of the Old English alphabet.
Commoners typically didn’t write things down - that was left to the poets and monks. They’re responsible for adding the runes. Some are similar to their modern-day counterparts, including B, R, S, and T.
They also included combinations (th, ei, ae, ng, ea, st) with single symbols.
Where it becomes complicated is - the placement of vowels and consonants determined how they were pronounced. I’ll save that for another time.
You can see, though, how it’s easier to understand original Old English works verbally than it would be to make an attempt to translate the written word.