Eamusne – and more generally direct questions in the present subjunctive, in particular in first person – will generally be understood as the deliberative or dubitative subjunctive (coniunctivus deliberativus/dubitativus). This type of subjunctive is called so because the speaker is weighing his options, or wondering if he should take a certain course of action or not. So
Eamusne?
translates to:
Should we go?
(I guess Eamus an non? can probably have a hortatory undertone, like asking “Are we going or not?” in English, but in general it is an open question.)
Often the deliberative subjunctive can take on a polemical character, especially in the past (imperfect subjunctive), e.g. Quid facerem? can, depending on context, be translated as “What was I to do?” or as “What was I supposed to do?”