Где находятся кассы?

Кассы - booking offices.
But it's not just Кассы, they're железнодорожные! Железная дорога - railway; literary - iron road. So, железнодорожные кассы - a place, where you can buy railway tickets.
В соседнем здании - in the next building. (literary -neighboring. Сосед - а neighbor).

Железнодорожные кассы находятся в соседнем здании. Находятся - "are situated", in everyday speaking this word isn't necessary, but in writing use quite regularly.

Здесь жил и работал...

A memorial plaque at one of the Moscow buildings

Художник - a painter.

Русский художник - russian painter, of course.

Выдающийся русский художник - оutstanding russian painter.

Жил и работал - past tense for жить -to live, работать - to work

The memorial plaque is placed at the building wall, and, naturally, выдающийся русский художник жил и работал in this building - в этом доме.

Аполлинарий Михайлович Васнецов lived in the beginning of xx century painter, but he was encouraged by ancient times.

Металлоремонт... And other very important services

So many words! And only 8 services.
The key word here is МЕТАЛЛОРЕМОНТ, which contains two roots - "металл" - metal, "ремонт" - repair. You can fix something metalic in this office.
What exactly?
Изготовим срочно ключи
Cрочно - urgently. Ключи - keys. Изготовить - here, the same as "сделать" - to make

Ремонт замков, зонтов
Замок - a lock, зонт - an umbrella

Ремонт застёжек "молния"
"Молния" is just a zipper at your bag or jacket. Застёжка - fastener

Кнопки на сумки
Кнопка - snap fastener. This word also means "a push-button". Сумка - a bag

Карабины - clevises. Well, mountain climbers always use them

Замки - locks, as we already know.

And the last one - Ксерокопия. This word also contain two roots: "Xerox" and "copy".

Терять смысл... Терять вес

A FITNESS CLUB ADVERTISMENT

С тех пор, как он ушёл, жизнь потеряла смысл...

Он ушёл - he left (here it means "he left me, "we broke up")

C тех пор, как - ever since

Жизнь потеряла смысл - life lost its meaning; there's no point to live. Потерять - to lose.

Лучше терять вес, чем смысл жизни

Терять вес - to lose weight. (Терять - to lose, потерять - to lose, too... How is it possible? Терять - NSV aspect, потерять - SV. You can find info about verb aspects in any Russian teachbook)

Смысл жизни - a point of life

Лучше ... , чем - a comparison. It's better to .... , than ....