Assume the files are textual, and not too big (e.g. less than 10000 lines).
Then you might try using head(1) (maybe as
head -vn -0 file* with GNU head) like this
head -10000 file1 file2 file3
Remember that some files are binary, that is they contain something else than text. For example, a core dump, an sqlite database file, a PNG image, an executable file, or even some OpenDocument file created with LibreOffice. On such files, using
head (or cat(1)) don't give nice results, because they are not text files but contain a sequence of almost arbitrary bytes.
You might be also interested by the file(1) command. It tries to guess what is the content type of a given file. Read also about media types (or MIME types)
Remember that on Unix like system a file is actually an i-node and could have several names (see inode(7), link(2), ln(1) for more). The name of a file don't means much. A file basically is a sequence of bytes with some way to name it. How that sequence is used depends upon the program accessing the file.
You could be interested by
xdg-open which tries to show, in a graphical manner, various kind of files (it is adapting to the content of those files).
Read also about globbing. See glob(7). Maybe learn about the
for builtin of your shell. Read about
bash looping constructs.