The office in my condo will do this for me for a small fee. Perhaps your friend's condo does the same, assuming they live in a condo.
To answer your question. The TM30 is required to filed next business day of your arrival. However, it's really only necessary if you plan to get an extension or if you get yourself in trouble such that immigration officials look at your paperwork.
- walking street - full of bars and tourists, local expats go to soi bakhao
- Soi bakhao, bars and fewer tourists prices are a little less. Place is probably more wild than walking street.
- Beach road - day time. Its hot and the beach isn't that great. There are some activities. Its a little more interesting than a hotel room
- Beach road - night time. It's a freak show. Definitely worth a stroll for an hour
- Beach road - late night. It's a freak show but a different kind of freakshow. Definitely worth a stroll for an hour
- Beach road is pretty safe but I recommend not taking valuables. I read stories frequently of people getting robbed. Those people tend to wear flash jewelry making them easy prey. Other wise you are safe. There are some other beach road warnings, I leave to you to google
- Soi 6 - you should google it. Its Beach Road Soi 6. Again a freak-show but with the stroll.
- You can find whatever you need in Pattaya when you are in Pattaya.
Songkran in Pattaya lasts two weeks. I have never gotten an eye infection. I find songkran to be a blast. Its also pretty easy to avoid the festivities. You will likely get wet at some point but you don't have to 'play water' if you dont want to, just avoid the tourist area.
Koh Larn is a popular tourist destination. I have been there via private boat so I am sure what tour operators offer. The beaches are nicer. Again, I will leave that for you to google, but that is the place 'wholesome' people go.... Not walking street.
There are two visas to consider.. The wife visa and the fiance visa and they have different requirements. I looked into this about 10 years ago and in my situation the fiance visa made more sense.