When does puberty for male start?

I had a couple of questions:

(1) When does puberty for male start?

(2) How do I make up for my Qadha prayers?

(3) How can I strengten my iman?

(4) How can I avoid Satan during namaaz?

بسم الله الرحمن الرحيم

(1) The sign of buloogh (puberty) is either wet dream or ejaculation, otherwise when a boy reaches 15 years (by lunar months) then he will be considered as baaligh (adult, mature):

بلوغ الغلام بالاحتلام والاحبال والانزال، الخ۔فان لم یوجد فیھما شيء فحتی یتم لکل منھما عشرة سنةً، بہ یفتی (شامي: 9/225-226، ط زکریا دیوبند)

(2) You should contemplate the number of years and months after your buloogh during which you did not offer the prayers. Then start performing the qaza. And, in contemplation you should opt for the maximum assessment. For example, if you are doubtful about 2 or 3 years then prefer 3 years; since if you make qaza of extra days it will certainly not go waste. And, while doing qaza make intention that you perform the qaza of first Zuhr salah, and likewise next time make intention of performing qaza of first Asr salah.

(3) Hazrat Abdullah bin Umar (رضي اللہ عنہ) narrates from the Prophet (صلّی اللہ علیہ و سلم) that the hearts also get rust as the iron gets rust from water. He was asked then how to cleanse it then? The Prophet (صلّی اللہ علیہ و سلم) said: Keep on remembering death and reciting the Holy Quran. (Baihaqi, 2/352, Hadith No: 2014). You should study such Ahadith that are connected to Iman. Maulana Yusuf Sahib has collected such Ahadith in a book named Muntakhab Ahadith.  In Bukhari Sharif there is a saying of Hazrat Muaz bin Jabal: Let us sit together and refresh our Iman for awhile. Therefore, one should discuss iman and other things related to it. As the discussion of dunya (material world) gets in to heart, the discussion of iman also in-sha-Allah will inculcate the significance and importance of iman in to our hearts. Moreover, you should adopt the company of any pious person who is adherent of Sunnah and having correct Islamic beliefs.

(4) The salah should be offered thinking that we are seeing Allah; if you can not centralize this thought then you should think that Allah is seeing us. While performing salah, the attention should be towards Quran. If there is any other thing that interrupts you, it should not get your attention. It is not bad that any thinking comes in salah, but the bad is that you yourself draw the attention to any thing or focus on it.

Allah knows Best!

Darul Ifta,