Most trekking and tour packages on this platform are batch-based by default, which quietly solves the biggest worry solo travellers have: you're never actually alone on the trip itself, just travelling there without a companion. That makes easier-graded, well-established treks and tours a genuinely practical entry point for solo travel, rather than something requiring a separate "solo" product.
The one cost detail solo travellers should watch for is the single-supplement charge some operators add for solo occupancy in twin-sharing rooms or tents - not universal, but common enough to check before booking. Below is a live, filtered view of easier-graded packages well-suited to joining as a solo traveller.