It is best to get around in Bangkok on the skyrail and metro if you can; they are really pleasant very easy and cheaper than a tuk tuk or taxi.
Getting Around Thailand
When in Thailand, try to have a map on you. If you ask a Thai person for directions, the answer is often a vague wave of the hand and an ‘over there’, which never seems to work!
If you want to get your phone unlocked and get a new sim in Bangkok, go the the massive MBK shopping centre next to National Stadium skyrail. Just go to the 4th floor.