Tabriz is a city in northern Iran.
Tabriz is the second largest city of the country, it belongs to the Azerbaijan region, people, speak Azeri (very similar to Turkish) as first language and are still quite different from others Iranian. Entry of Iran, both coming from Turkey or Armenia, it's the most transited crossroads for all hitchhikers and travelers coming from Europe and going to Asia.
South West towards Urumia and southeastern Turkey or Iranian Kurdistan Sanandaj, Kermanshah and Hamedan
Take the western ring road, from the centre you easily find public buses, ask for the railway station and stay on the bus until it turns out from the main road. At Serdrud village starts the motorway coming from the southern ring road. Start to hitch here. Traffic will keep very high, and majority of cars stopping will be taxis but with a clear panel "No taxi", better written in Persian, you will call the attention and people should easily stop and pick you up. Before Mamaghan you will find the junction, to Urumia and Turkey or Miyandoab and Iranian Kurdistan.
Take the eastern ring road, there are buses, taxis for less than eur 0.50, or trucks you can hitch. Go till most eastern point of the city, where it starts the southern ring road, at that junction start the motorway to Zandaj, and you should be out of taxis, the same panel, no taxi will help you as well.
North towards Khoy and eastern Turkey or Jolfa , Azerbaijan and Armenia
Go to Azerbaijan square and keep walking a bit out of the city. Traffic will keep very high, and majority of cars stopping will be taxis but with a clear panel "No taxi", better written in Persian, you will call the attention and people should easily stop and pick you up.
Accommodation and Sleep
In Tabriz there is a very large Couchsurfing community with some few members very active (hosting every day). You shouldn't have problem to find a host. If not, in case you need to camp there are lots of nice parks all around the city. Shah El Goli park south of the city, is full of terraces perfect to camp, and also Eyanli forest (east of the city) is perfect to camp, water, bathrooms and an amazing view; be prepared to walk hard and steep to deserve it! (on Friday it's overcrowded of people coming there for the weekend, you will easily find someone sharing his food with you and also inviting you at home)