He wants to open a shop but he needs training where he will be forced to taste sweets containing alcohol and gelatine

Praise be to Allah.

With regard to alcohol, it is haraam to consume it, carry it, sell it or buy it. Ten categories have been cursed with regard to it, as it says in the hadeeth narrated by al-Tirmidhi (1295) and Abu Dawood (3674) from Anas ibn Maalik (may Allaah be pleased with him) who said: The Messenger of Allaah (peace and blessings of Allaah be upon him) cursed ten with regard to alcohol: the one who squeezes it (the grapes etc), the one for whom it is squeezed, the one who drinks it, the one who carries it, the one to whom it is carried, the one who pours it, the one who sells it, the one who consumes its price, the one who buys it and the one for whom it is bought.”  

Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi. 

It is not permissible to put alcohol in the sweets or to taste these sweets, even if that is for the purpose of study or to get a certificate which will allow one to work, because that is not a case of necessity that makes it permissible to commit a haraam action. 

With regard to gelatin, some of it is halaal and some is haraam. This has been explained in the answer to question no. 210. Whatever is haraam, it is not permissible to put it in the sweets or to taste it. 

You should note that there are many halaal ways of earning a living, and that if a person gives up something for the sake of Allaah, He will compensate him with something better than it. Allaah says (interpretation of the meaning): 

“And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty).

3. And He will provide him from (sources) he never could imagine. And whosoever puts his trust in Allaah, then He will suffice him. Verily, Allaah will accomplish his purpose. Indeed Allaah has set a measure for all things”

[al-Talaaq 65:2-3]

The loser is the one who sells his religious commitment for some transient worldly gain, and he will not gain anything from this world except what is decreed for him. 

And the Prophet (peace and blessings of Allaah be upon him) said: “The Holy Spirit (Jibreel) has inspired to me that no soul will die until it has completed its appointed term and received its provision in full, so fear Allaah and do not be desperate in seeking provision, and no one of you should be temped to seek provision by means of committing sin if it is slow in coming to him, for that which is with Allaah can only be attained by obeying Him.” Narrated by Abu Na’eem in al-Hilyah; classed as saheeh by al-Albaani in Saheeh al-Jaami’, no. 2085.

We ask Allaah to provide for you from His bounty and to make you independent of means by that which is halaal so that you have no need for that which is haraam. 

And Allaah knows best.