Dining rooms need one additional piece of furniture (like a sideboard/buffet) besides the actual table and chairs. The best place would be on that larger back wall, but if there isn't enough room, then put something like a glass and gold bar cart on the smaller wall next to what appears to be the tiled entry way. You need to decide that furniture piece before you pick out what to hang on the walls and where.

When I have a big wall I always do a collage. You can do it tons of different ways. You can use frames all the same size for a symmetrical look, all different sizes, even add metal wall art, mirrors or baskets, etc. for a more eclectic look. A few rules to follow: Keep all the frames the same color for cohesion. Keep the spacing the same between every piece for a more put together look. I usually do 1.5"-2" spacing.

The prints can be $$$ so I have also provided the links to similar style prints. https://www.perigold.com/decor/pdp/wendover-art-group-oculus-6-by-thom-filicia-picture-frame-painting-on-paper-ezxr1506.html?&experiencetype=1 https://www.art.com/products/p39454204493-sa-i9893796/megan-morris-circular-strokes-i.htm?upi=PWJ8TBFWY11 https://www.gallerymonkey.com/Abstract-Circle-2-Art-Print?language=en&currency=USD https://www.walmart.com/ip/Morris-Megan-12x12-Gold-Ornate-Wood-Framed-with-Double-Matting-Museum-Art-Print-Titled-Circular-Strokes-II/2944121072?wmlspartner=wlpa&selectedSellerId=15301

Judianna20,  What a nice assumption you've made of someone you clearly don't know at all. I won't be as snarky as you to think ill of someone else's intentions. I might have the PRO distinction on my name but I am not looking for any customers or clients. Believe it or not, some of us enjoy helping and giving advice and have a passion for interior design, beyond the call of money. I have been a frequent Houzzer of many , many years before I became a PRO, so I am aware there are very rude people on here, but I didn't think anyone would stoop so low to judge my words and assume I am begging for clients. I am currently not taking clients and only here to help others, which is common for many Professionals on Houzz. Did you have any advice or suggestions to give OP? Or did you only intend on gatekeeping this thread out of your wrong assumptions that I'm looking for clients? If so perhaps you should give some advice to OP or report my comment if you feel so slighted.  It is unfortunate this forum is for home advice but some people like to gatekeep. Sorry OP, if you're still even there, but I still stand by what I said, if you want help please let me know. I promise I won't ask for a dime from you, those aren't my intentions. I merely enjoy what I do.  A little upsetting I have to even discuss this in the first place.  Kind regards, Solid Form