So far you were the only person with access to your home. But you can share HomeKit with your family too. Actually you could share it with anyone that you choose to. All you need is their Apple ID (appleid).
To share your home click on the home icon, and choose ‘Home Settings’. You’ll see a section called ‘People’, and the option ‘Invite People…’ Click it and choose someone to invite. You will notice that the people in your family (when you use Apple’s family sharing) will already be present, and you can just select them. Otherwise you can just an appleid. It looks like an email address and it will show up in a colour if it is recognised as an appleid.
Go ahead and send the invite. You will that it is pending until the invitee accepts or rejects the invitation.
Once a person accepts you can finetune their HomeKit access. You can choose whether they can also use it away from home (remotely) and whether they can Add and Edit accessories.
Editing allows this person to add and remove accessories, scenes and other people in this home. And some automations.
At all times you can remove people again from HomeKit. The first person (in this case you) that connected to (paired with) the home is the boss. You can not be removed. And you can always control accessories remotely and add and edit accessories.