All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is permissible for a person to keep a distance from those who waste his time with other than the obedience of Allaah; rather, he should keep a distance from them and avoid mixing with them. We do not mean by this to completely desert people but to avoid mixing if it involves wasting time without any benefit, especially after ‘Ishaa' prayer, as the Prophet disliked sleeping before ‘Ishaa' and talking after it. [Al-Bukhari and Muslim]
Imaam An-Nawawi said: "The reason why it is disliked to talk after ‘Ishaa' is that it leads to staying up late and it is feared that the person may end up sleeping all night instead of waking up for the voluntary night prayer or mentioning Allaah, or for the Fajr prayer at the time of permissibility, or its preferred or best times. Also, staying up late makes a person too lazy during the day to perform the Islamic obligations, acts of obedience and the worldly affairs. The scholars say: It is disliked to talk after ‘Ishaa' when it is about matters of no benefit. As for beneficial matters and matters of goodness, it is not disliked."
Indeed, life is too precious to be wasted in gossip, idle talk and matters of no benefit. Ibn Al-Qayyim said: "Excessive mixing is an incurable disease that leads to all evil; how much blessing was deprived because of mixing, and how much enmity has it sown, and how many feelings of hatred and animosity has it instilled in the hearts of men; big mountains may disappear but such feelings persist! Excessive mixing is a loss of this worldly life and the Hereafter. Rather, a servant should mix only according to need, and he should look at people according to four categories. If he mixes one category with the other, without discerning one from the other, evil will inevitably come to him.
The First Category: the person with whom mixing is like nutrition that is indispensable in the day and night; but once one takes his need of him, he quits mixing. When he becomes in need of him again, he mixes with him again, and so forth. This category is rarer than red sulphur [a metaphorical expression in Arabic which means it is scarcely found]. Those are people who have knowledge of Allaah - who know His orders and the plots of His enemies, and the diseases of the heart and its medicines, and those who are sincere to Allaah, His Book, His Messengers, His creation. All profit is in mixing with such people.
The Second Category: those with whom mixing is like medicine; one needs it when he is sick. As long as you are in good health, you do not need to mix with them. They are those with whom one is obliged to mix in order to serve the interests of subsistence, and to fulfill one's needs, such as with transactions, partnerships, counseling, and treatment for illnesses. Once you achieve your need from mixing with such people, then mixing with them ends up being mixing with the third category.
The Third Category: Mixing with them is like a disease with its different stages, types, strengths and weaknesses.....
The Fourth Category: mixing with this category is total devastation. It is like eating poison; so if one has the antidote at the same time, he is safe; otherwise, he is as good as dead. Indeed, many people belong to this category - may Allaah not increase their numbers! They are the people of heresy (innovations) and misguidance who obstruct the Sunnah of the Prophet of Allaah and preach what opposes it. They are those who turn others away from faith in Allaah and seek a crooked path."
For more benefit, kindly refer to Fataawa 83503 and 133933.
As regards the question of whether it is obligatory to inform all of your friends about the marriage, then the answer is no. Also, there is no minimum or maximum number that one is obliged to inform, but it is Sunnah to organize a wedding celebration where the marriage would be announced, and it is also Sunnah to invite others to food. The Fiqh Encyclopedia reads: “The Islamic jurists have said that it is desirable to announce the marriage, and to beat the Duff (tambourine with no cymbals) during the celebration so that the marriage is recognized and discerned from fornication or adultery; as the Prophet said: "Announce the marriage, make it in the mosques, play your Duffs for it, and one of you should make a Waleemah (i.e. marriage banquet) even if it is over one sheep.” [At-Tirmithi and Ibn Maajah]
Therefore, if you made the marriage public and made a Waleemah for it by inviting some of your friends, or relatives or neighbors, then this is sufficient.
For more benefit on the conditions of a valid marriage, among which is the attestation of two witnesses, please refer to Fatwa 92544, where we clarified that declaring the marriage is better in any case but if there were only two witnesses, then the marriage is valid.
Also, for more benefit, you may refer to Fataawa 131281, 128661 and 89921.
Allaah Knows best.