Nickelini,
Lots of good information in the previous replies! A few thoughts.....
Lauterbrunnen is the transportation hub for the valley, so it's a bit "busier" but I don't consider it overly "touristy". That's also my preferred location to stay as there are some nice hotels there and it's central to all the other locations you mentioned so it makes a good "home base". It gets a bit less sun that the villages higher up as it's on the valley floor, but I still consider it to be very scenic.
Gimmelwald is very small and tends to be quieter and less busy than the other locations. The evenings there are very quiet (almost boring) but a nice place to "chill". The Mountain Hostel tends to be a hangout for visitors in the area. As I recall they have a bar which even people not staying at the Hostel can visit.
The Jungfrau is a day trip location and a one of the most expensive trips that you can take in that area. I don't believe it's possible to stay up there (the closest location with hotels would be Kleine Scheidegg). It's not an area that would appeal to me as a location to stay. If you decide to visit the Jungfraujoch, it's important to check the weather prior to going there, as it won't be as pleasant an experience if the mountaintop is shrouded in fog. If you have altitude issues, that needs to be considered as the top is at about 12,500 feet.
Wengen is located on the opposite hillside from Mürren. It's very scenic but a bit larger, more touristy and posh than other locations in that area. It's also a "car free" village.
Grindelwald is considerably more "touristy" (IMHO) with larger and fancier hotels and souvenir shops selling the usual items. It's very popular for skiing in the winter and I believe some Olympic events have been held near there. One reason it's a bit larger is probably because vehicles can easily reach it, which means that tour buses can also reach it. It's very scenic but probably my least favourite of the towns in that area.
You didn't mention Mürren, which seems to be an overwhelming favourite with many here. It's a very scenic village with some good hotels and good hiking opportunities. One easy trip is to take the Allmend-Hubel Funicular up the hill and then hike (stroll?) back to Mürren, through pastoral alpine meadows and past grazing cows. Mürren is also a good place to stay if you're planning to take a trip to.....
The Schilthorn / Piz Gloria. This was made famous by the James Bond movie On Her Majesty's Secret Service back in the '60s. There's a revolving restaurant at about 10,000 feet which is a great way to see the Eiger, Monch and Jungfrau while enjoying a fine meal. Like anything else in Switzerland, getting there is a bit pricey but it's a trip I always enjoy as the cable cars are spectacular.
The Matterhorn is some distance from the Lauterbrunnen Valley, so with only 2 -3 days, I'd probably skip it this time.
If you're planning to use a lot of the mountain lifts in the area, you might have a look at one of the Swiss Passes. You may find this to be helpful - https://www.ricksteves.com/travel-tips/transportation/trains/switzerland-rail-passes .