Well I used table coding to make my infoboxes and I used adjustable expressions to spice up the design. Hielmiez's links that they provided are about portable infoboxes, which is kinda advanced for me despite being mobile friendly. Table coding isn't kinda mobile friendly but it is the least I can do to make a basic infobox to start with until an experienced coder volunteers to make a portable version.
As for "adjust expressions," you may need to search for HTML glossary sites to learn how to adjust design variables. That's intermediate design stuff but understandable to me.