The dilithium dimer exists- but it isn’t particularly common, and we usually only see it in the gas phase.
Essentially, the 2s electrons interact and form a bonding orbital. (s-p mixing is particularly pronounced here, but I presume you don’t know MO Theory.)
Due to the diffuse nature of lithium’s atomic orbitals, the bonding is pretty weak; and the inter nuclear distance between the 2 lithium atoms is actually quite large.