For tea-house treks you do not need camping gear. Focus on layers: a base layer, a warm fleece, a down jacket and a waterproof shell.
Bring broken-in boots, a sleeping bag rated for cold nights, a head torch, sunglasses and sun cream. Many items can be rented cheaply in Thamel.
Most importantly, bring travel insurance that covers trekking at altitude and helicopter evacuation, and check the maximum altitude your policy covers.