I’m going to be hopefully getting my own place soon and I need advice on a dog breed

HIII so basically I can’t live on my own well as I’m quite an anxious and fearful person so I require a buddy to keep me company. I have never owned a dog before but I have done quite a lot of dog sitting. I’m a very active person (I walk for at least 3 hours a day) I enjoy being outside more than inside I love to have my brain occupied so doing training and playing will lot be the best thing to distract my brain. I’m unsure whether I’ll be moving into a flat or house rn. I need need NEED a good protective dog but not like protective to the point they are wary of strangers.

And that’s it really.