There are many beaches and they are all numbered in case you need to find a specific one (Paal X). If you're lucky, you might see wild seals on the beaches. There's a beautiful red lighthouse at the tip of the island, but you need a bit more time (or a bike without a flat to see it).
Hiking, Dunes, and Heather
The National Park Dunes of Texel is the main place to see the dunes, but you'll see them all over along the west side of the island. The heather is in bloom all summer as well as slightly earlier (call to ask!). The heather is very dreamy and it is easy to locate it once you're on the west side of the island. I found it very dreamy.
The roads are set up for bicyclists and cars although cars are very respectful of bikes. You'll cruise through adorable small towns with many sheep, past heather covered dunes, through forests, and to the beginning of the beach. Some people drive, but biking is a sport here for a reason.
Check that your bike is in good condition prior to going as there's only two shops on the Island and they are both far from the ferry drop-off point. (Don't ride on a flat...)
It is very family friendly although I was impressed with how much information they gave about the lives of the seals. The seal pictured was one of the babies who lost his mother that they were preparing to release back into the Wadden Sea after learning to eat fish. You can even see into the hospital ward and I promise, the baby seals are adorable.
I'm quite obsessed with seals as is J, so after walking up and down the beaches looking for wild seals (and failing), we ended up here. Doing good feels good too.
Beer / Tesseltje'
Look for bottles of Tesseltje' Likorette. It is named in honor of a enlightenment era figure, Maria Tesselschade Roemer Vissche, who was a member of Muiderkring intellectual circle that met at the Muiderslot castle. The name Tesseltje' is a nickname bestowed on her as she lived in Texel. The Likorette is a very sweet spiced liqueur that can only be bought on Texel or at the Muiderslot castle. It does not list its ingredients (still a secret).
Cute Small Towns
Most visitors stay within the towns where you'll find the basics: a supermarket, a bike shop, cafes to sip coffee/beer in, and houses available for rent. These towns are so small that you can see farmland all around you, but it's part of the charm. We enjoyed just getting lost on the small streets admiring the flower boxes.
If you're not a vegetarian, the Bij Jef restaurant is the only Michelin Star restaurant on the Island and it serves locally sourced ingredients. On a budget, you can head to the nearby supermarket to make a picnic by the dunes or by the beach.
Getting There & Staying There
You'll find many options in terms of accommodations, but it is very hard to find something last minute in summer. Many places require at least 3-7 nights stay (as many Dutch families go for 1-2 weeks) although it's possible to find camping as well as inexpensive airbnbs if you book at least a month in advance. The market is a bit competitive (expect at least 100 euros a night for a bungalow).
Den Helder is a nice Dutch town with some surprisingly good food. They are redoing a block of former factories (you'll pass this on your way to the ferry) into a cultural center with restaurants and other attractions. We found a delicious Moroccan restaurant called Kunst & Kitchen with beautiful art decorations.