It depends on your threat model.
You can always import the seed into a new Hardware wallet and continue as if nothing changed, but consider this:
Your old addresses are tied to the purchase of the Ledger device. This can be a security concern.
If you want to truly start fresh:
1. Purchase a new hardware wallet (preferably not in your name) and generate a new seed phrase on-device
2. Backup that seed phrase immediately
3. Generate a few new addresses and progressively transfer all your funds to the new addresses over the next few days or weeks
But if you want to break the link between old and new completely, you'll need advanced techniques