In Python you can get file size using stat()
os.stat(path).st_size
And you can find file(s) using glob.glob with *, ? or **.
files = glob.glob("Folder/*/1.jpeg")
for path in files:
    print(path, os.stat(path).st_size)
It always gives list with all matching paths - even if found only one file or it didn't find any file.
If it may have file in Folder/sub1/sub2/sub3/1.jpeg then you can use ** and recursion
files = glob.glob("Folder/**/1.jpeg", recursive=True)
Of course you can use string formating (.format() or f-string) to search different files from list
for name in Lst:
    files = glob.glob(f"Folder/**/{name}", recursive=True)
Or you can use *.jpeg to get all files and later check if it on the list
files = glob.glob("Folder/**/*.jpeg", recursive=True)
for path in files:
    filename = path.split('/')[-1]
    if filename in Lst:
        print(path, os.stat(path).st_size)        
EDIT:
In Bash you can also use *
for path in Folder/*/*.jpeg 
do 
   du -bsh $path 
done
or in one line
for path in Folder/*/*.jpeg; do du -bsh $path; done
but it still needs to filter files which are on list.
But maybe it could be simpler to use { }
for path in Folder/*/{1,5,8,10,11}.jpeg
For more help in Bash you could ask on similar portals: Unix & Linux or Ask Ubuntu