I buy a “new to me” bike every couple of years and have done several 1x conversions. I use a bike gear calculator (gears.mtbcrosscountry.com) when deciding on a new cassette and chainring combination.
In your case going to a 28T or a 30T oval ring probably makes the most sense, but the gear calculator will let you see how a different cassette, a larger cog or even a different wheel size will effect your gearing.
A gear calculator is especially useful when converting from 2x/3x to 1x.