Ramen is a traditional Japanese dish served with broth, lo mein is Chinese
it is more like what some might describe as "stir-fry" - with a lighter sauce and add-ins like meat and veggies.
Both ramen and lo mein are wheat flour based noodles. The "traditional" ramen noodle frequently has the katsui that gives it a distinctive flavor and texture. The lo mein is closer to Italian spaghetti, the texture and flavor are somewhat different.
I can get fresh, dried, or instant where I live, hence my question about which type.