How should I build my first MTG deck for my first game to play my friend ?

This question is rough to answer without knowing what set your cards are from.

As far as color combination Black and Red support one another very well as well as Black and Blue. Black and Red would be all about killing his creatures before he has a chance to do anything with them. Black and Blue would be all about controlling his turn, blue to counter his spells and black to force him to discard cards and or kill the creatures you're not able to counter.

A good easy start if you do a deck is to focus on as few colors as possible. I would go with no more than 2 colors. Try to keep what your cards can do as tightly focused as possible. Its easy to let the neat pretty cards distract you, but trying to do too much with one deck will cause you to lose every time.

If you do black and red a good focus is to have red cards for damage, black cards for outright creature killing and some creature resurrection of your own and then choose some decent creatures from both colors.

The last thin to consider is your mana curve. You want to have a good number of low casting cost cards. Most of your deck should have cards that cost between 1 and 3 mana total to cast. You should have more in the 1-3 range than you do 4 and over. Also a good rule of thumb, but not always written in stone is try to have 1/3 of your deck be land. IE if you stick with the usual 60 cards then 20 of it should be land.

Once your done picking cards the best way to determine what lands you need is to count your mana symbols. For example if you have a deck of 40 cards and in that you have 25 black symbols and only 10 red ones then you want more black mana then red. If your symbols are about even you want an even amount of red and black land and of course if you have more red then black then you want more red than black lands. A good start for a new deck is to just grab 10 swamps and 10 mountains and then make changes as you see fit.

Just remember it takes time to get used to the game. Once you have played a few hands you might experiment with your other cards or try new things with the deck you made. Most importantly, it is competitive, but have fun.

- Never play more than a 2 color deck in magic, it is very hard to pull out the right color of mana.

- Two color decks work pretty well as each color has its speciality and combining 2 of these would be nice. (blue-countering or controlling, black-destroying/discarding and also some strong creatures too, white-gain life and they have good flying creatures, green-strong creatures, red-burn spells and direct damage

- since you have black cards just make a all black deck, i would suggest you put in some destroy creature spells which clear the path for your own creatures and just win by combat damage directly to the player.

well ultimately its your choice but i would make all one color to start. i have been playing for years and i still like single color decks. if you make a good enough one that holds though any deck then no reason to change it. i'd go with black for the destruction it has, although i have a red deck that has no creatures and almost never loses in one on one's with my friends unless i manaclump. but try to make it as fast as you can. a good card balance is 20 lands 20 creatures and 20 everything else.

Just stop messing with them or tell them to play something else. Not very many people like discard, especially in the first couple turns, but if they beat you on a regular basis it's coming across as hypocritical for them to whine about your deck.

if your a beginner.....i would go with the 2 color deck ....less colors ....faster and easier to deal with.....good luck....:)