Hi I live in Bangkok, in the heart of night life areas, here are some pointers.
1. when you arrive at airport make sure that you are caring more than 20,000 Baht (800 Cdn) in cash, traveler cheques as immigration is really making it hard for people to enter. 2. if you use a taxi always insist on a meter if they refuse don't get in, or get out of the taxi.
2. Take ask the taxi driver to take you anywhere as they will take you to places that they get a kick back and they will overcharge you.
3. For night live there are several places, one is Soi Cowboy which is on Sukhumvit Soi 23, which is okay, I was about 1 week ago and there where practically no customers, be careful in some of the bars there, as they tend to overcharge you for your drinks, and the lady girl drinks are expensive, and the girls will pester you to buy them drinks. as well as the barfines. My favourite bar there is Tilac, then Dollhouse, LightHouse and Shark.
4. Nana Plaza Sukhumvit Soi 4 across from Nana Hotel, I believe is better than Soi Cowboy right, it can be hit and miss now, prices aren't as expensive and the girls most barfines are 900 Baht and 2,500 - 3,000 for short time 1-2 hours and I think about 4,000 - 5,000 for long time (1Baht - 25.30 Cdn), I think are prettier. I highly recommend Spanky's (That's the one I go to all the time, I know allot of the girls there as well as the door girls, Mamason and the manager) on the 2nd floor on the left when you enter Nana, they seem by far to have the best and youngest looking girls, and the girls dance topless there, and if you see a girl on stage that you like you can call them over to sit with you and allot of them are hands on, where you can with their breasts.
5. For daytime action starting around 1pm there is the famous Beer Garden on Sukhumvit Soi 7 about 20 meters down Soi 7 on the left. They are all freelancers, so you can negotiate how much you are willing to pay. I would pay more than 1,500 - 2,000 for short time. There is also Gullivers on Sukhumvit Soi 5, it is a large place and they have pool tables, good food and freelancers (I haven't been there in about 2 years). There are also hundreds of massage places.
6. If you are more into the clubs there are Several on Sukhumvit Soi 11, You have Oskars, Levels, Insomina. I never been in these places but I live right near there and the girls I see are pretty pleasing.
7. Traffic can be very bad most of the time, just to go 1km, could take you 20 minutes, I recommend that if you are staying along Sukhumvit, then you best is to take the Skytrain (they call it BTS here)
8. If you have to exchange money there are currency exchange booths everywhere, but I recommend using Vasu on Sukhumvit Soi 7/1, they give you the best exchange rate. Also keep in mind that in Bangkok the on the south side of the main roads is the even Soi's and on the North Side is the odd Soi's. Here is a website, that might be useful to look at.
www.thaivisa.com. I would avoid the escorts website/agencies as they are ripoffs, You can also use Wechat, Tinder and Smooci.com.
One last thing if you are going to neighbouring countries, try to fly out of Survarnabhumi airport and not Don Mueng, as immigration offices at Don Mueng are assholes, and find any reason to not let you in. You can send a PM if you have any other questions.