Hi, you haven't made many grammar errors, but I think that if this is a report of some kind, you'd want to make it a bit more stylish, and that's what I tried to do. Hope I helped. Cheers!

Traffic in Granada is a bit chaotic. There are usually numerous traffic jams. So if you visit Granada it’s better to leave the car parked in a car park and to use the public transport. 
There are several types of public transport in the town, namely busas the coach, taxi, underground (or you could write – metro, everyone understands that) or tram. There is also a small tourist train that takes you on a tour  to the most characteristic monuments of the city such as the Alhambra, the Cathedral and the neighborhood of “Albaicín”. 
If you want to get from the suburbs to the town center, the best option is to take the underground or tram. Both are faster than the coach, but are a bit more expensive. 
Once you reachin the downtown, there is a large pedestrian zone where you can walk freely. In some streets of downtown Granada, passing car traffic iss are allowed, but speed is limited to twenty kilometers per hour. However, the streets are too narrow and the traffic passage of lorriesLorries or vans isare not allowed. 
People living in Granada knows are well aware of well the traffic problems that exist ofin their town and that’s why many of them so many people use the scooter to move faster, or catch the bicycle on the cycle lane, which is healthier and does not pollute the air. 
How long does the tram take from the suburbs to the downtown? 
It takes about twenty minutes. 
My train arrives at quarter past eight. Do you think you could pick me up at the station? I'll be  waiting(you use future perfect continuous because you are describing an action which is going to happen in the future and is going to last for some time). on the platform number three.

And a refined version - with all coreections accepted:

Traffic in Granada is a bit chaotic. There are usually numerous traffic jams. So if you visit Granada it’s better to leave the car parked in a car park and use the public transport.
There are several types of public transport in the town, namely bus, taxi, underground (or you could write – metro, everyone understands that) or tram. There is also a small tourist train that takes you on a tour to the most characteristic monuments of the city such as the Alhambra, the Cathedral and the neighborhood of “Albaicín”.
If you want to get from the suburbs to the town center, the best option is to take the underground or tram. Both are faster than the coach, but are a bit more expensive.
Once you reach downtown, there is a large pedestrian zone where you can walk freely. In some streets of downtown Granada, car traffic is allowed, but speed is limited to twenty kilometers per hour. However, the streets are too narrow and the traffic of Lorries or vans is not allowed.
People living in Granada know are well aware of the traffic problems of their town and that’s why many of them use the scooter to move faster, or catch the bicycle on the cycle lane, which is healthier and does not pollute the air.
How long does the tram take from the suburbs to the downtown?
It takes about twenty minutes.
My train arrives at quarter past eight. Do you think you could pick me up at the station? I'll be waiting(you use future perfect continuous because you are describing an action which is going to happen in the future and is going to last for some time).On the platform number three.

Could anyone correct this?

Traffic in Granada is a bit chaotic. There are usually numerous traffic jams. So if you visit Granada, it is better to leave the car parked in a car park and to use public transport.
There are several types of public transport in the town, such as coach, taxi, underground or tram. There is also a small tourist train that takes you to the most characteristic monuments such as the Alhambra, the Cathedral and the neighborhood of Albaicín.
If you want to get from the suburbs to the town center, the best option is to take the underground or tram. Both are faster than the coach, but are a bit more expensive.
Once in the downtown, there is a large pedestrian zone where you can walk. In some streets of downtown passing cars are allowed, but speed is limited to twenty kilometers per hour. However, the streets are too narrow and the passage of lorries or vans are not allowed.
People living in Granada know well about the traffic problems that exist in the town and so many people use the scooter to move faster, or catch the bicycle on the cycle lane, which is healthier and does not pollute the air.
How long does the tram take from the suburbs to the downtown?
It takes about twenty minutes.
My train arrives at quarter past eight. Do you think you could pick me up at the station? I'll wait on the platform number three.