Spanish Dance (Davis) isn't too hard ... 2 timpani, snare, castanets, suspended cymbal and xylophone.

Balinese Sunrise is one of the least technical grade 1s but it does require instruments you probably don't currently own. It is in the Campbell/Hill multiple percussion solo collection. Other solos here don't require as much equipment but I think they are difficult to memorize and perform well.

Engine Room is a perennial solo at TSSEC. Easily achieved but needs lots of stuff and help to move.

Also consider the tenor drum solos. Journey through Time is the earliest grade 1 blue book solo, but I would not necessarily consider it easy.

Prelude and Jubillo

My go-to is Prologue and Jubilo by Jared Spears. I have my freshmen play this every year.