Help with Roman(?) bronze coin

I received this coin as part of an assorted lot. I think it might be Roman, but I don't know whether it is real or a modern replica, etc. I really don't know anything about ancient coins. Can anyone help identify this or at least give me a starting place to begin looking? Thanks!

Diameter is roughly 17mm, weight is about 2.4 grams.

It is similar, but not identical to this coin:
https://en.numista.com/catalogue/pieces58187.html

I think the legends are the same except for the SMNB at the bottom of the reverse. Mine has four letters that I can't really read, but I don't think they are SMNB.

Can anyone offer any advice on this coin? I think I've identified it as Valens but any more detailed info would be great, especially an estimate on value.

It does appear to be Valens, but there a quite a few options, can you make out any of the letters below Victory's feet on the reverse?

Valens, AE3,DN VALEN-S PF AVG, pearl diademed, draped cuirassed bust right / SECVRITAS-REIPVBLICAE, Victory walking left, holding wreath and palm branch

http://www.wildwinds.com/coins/ric/valens/t.html

I'll take a closer look later and see if I can narrow it done given a list of possibilities.

How do I know what the denomination is with these Roman coins?

It's a small bronze coin; therefore, it's a follis (but when researching, just look for AE, which is the symbol for bronze).