I was going to give you some hiking recommendos but that’s probably no good in April. I stayed in Murren a few days last summer.
The Lauterbrunnen Valley is absolutely gorgeous. Stop in Wengen on the way up or down from Jungfrau. Walk through town on the main drag up to a small church on the left. Great view of the valley from there. Trummelbach falls in the valley is impressive. And views from Mürren are amazing. If you have a clear day make a loop taking the bus from Lauterbrunnen through the valley, stop at the falls, ride the tram up from Stechelberg to Gimmewald to Mürren, train and tram from Mürren back down to Lauterbrunnen. Or reverse order. Could take a lift up higher above Mürren if you want. Hotel Bellevue restaurant was very good.
Thun castle and old town. There’s a shop in old town that has great selection of craft beer, wine, and chocolate. It’s called Simply Fine I think.
Could easily go to Bern one day as well.