Hello guys, I am used to script for San Andreas Multiplayer and since the game doesn't work anymore for me I decided to learn and make a game on my own, so I need few advices.

I installed Unity and chose to make 2D game until I learn the basics, can you guys tell me about a good program for sound effects also any advices that you have.

And a question, if I want to make a multiplayer game like 2D pvp, 2v2, how do I host the game so both players can connect? Do I need mysql knowledge?

can you guys tell me about a good program for sound effects

FreeSound.org <-- Free sound effects (look at the licenses to make sure you can use them commercially, if you plan on selling your game, and make sure you attribute the creators of each sound).
Audiacity for basic editing.

also any advices that you have.

Start small, add features one by one, complete projects you start, don't start projects you can't complete.

And a question, if I want to make a multiplayer game like 2D pvp, 2v2, how do I host the game so both players can connect? Do I need mysql knowledge?

No, SQL is a language for talking to databases (and MySQL is a database system). You don't need a database at all, especially not for such a small game.
And databases aren't directly related with hosting servers or making computers talk to each other - it just happens that databases are commonly used with those things also, but aren't required by them.

To host a server, you need:
A) A program that you write (called a 'server') that handles the logic of your game and coordinates between the 'client' programs that run on your players' computers.
B) A computer (also called a 'server') that'll run your server-program.

You can run that computer yourself, which is good for development, but you probably don't want your computer publicly exposed to the internet, so usually people hire a company to 'host' the server-software (the program you write) for you on their server-hardware (their computers).

You can either rent the hardware in such a way where they handle almost everything for you except writing your actual program (many such companies exist), or you can rent the hardware in such a way where you can micromanage it yourself (Rackspace, Amazon.com, Google, and Microsoft, are the big names in this area).

Well, I will see what I can do, I barely know how to send a message xD

Do you guys know a list where I can find all functions of monodevelop because mine don't have hints or autocompletion..

If you're on Windows don't use monodevelop, use visual studio instead which is miles ahead.

And there's no "full list of functions" as there aren't a few dozens but tens of thouthands, you won't get an exaustive list, you need to explore and learn starting by picking a book on C# (not related to games at all). Do expect a long road ahead :)

To host a server, you need:
A) A program that you write (called a 'server') that handles the logic of your game and coordinates between the 'client' programs that run on your players' computers.
B) A computer (also called a 'server') that'll run your server-program.

Dont agree with that, depending on the type of multiplayer wanted you may also host the "server" part of your software on same mashine the player runs the game or even dont use any server and communicate over UDP. Networking is an own subject itself not in game development only but in any other area where functions are outsourced.

You should learn about network architecture, communication layers and protocols before concepting your game because this is a major design decision from the beginning. Balancing pvp games at least against ping leaks and package loss is the most important thing in design conception that results in players rage quit your game when the item they got or the critical hit they made to the opponent gets rewinded from the server caused by a leak in game communication between client/server.

I work in games industry for a couple of years and "quickly adding multiplayer support to the game later" did never succeed in every project I was involved to rather than ended in several months of "fixing" the game to get multiplayer working. Async game features are heavly difficult to debug especialy in unity where you dont have full access to the mono runtime and that is what client/server games are working with, asynchronous message handling.

I also would quess not to use unity(s build in network features) because the networking features they have are way limitted and as I remember correctly a pro feature. As I never worked with that so deeply I dont know if the included mono runtime supports the .Net networking library but if so or if you plan to bring your game onto Windows only then you should strictly use at least that or take some networking package from the asset store

You can either rent the hardware in such a way where they handle almost everything for you except writing your actual program (many such companies exist), or you can rent the hardware in such a way where you can micromanage it yourself (Rackspace, Amazon.com, Google, and Microsoft, are the big names in this area).

Well, for learning purposes, you can opt for free limited servers also!

• Cloud9
• Codeanywhere
• Nitrous.IO
• Koding

Of course, you'll have to do a bit of research for setting up each environment.

For sound effects, FMod is perhaps the most popular commercial game audio solution (it or wwise). Recently they launched FMod.io which you can see in action in this video. The cool thing about fmod.io is its a massive collection of royalty free audio effects for like a buck a piece. Best part is, you get 50 free to start. For many games, 50 is more than enough.