Let me make a few suggestions about the text you've translated, martunia.
1) ...live nearby Cracow. - the word 'nearby' is both an adjective usually used attributively (jako przydawka - pobliski) - and an adverb (e.g. 'I live nearby' - 'Mieszkam w pobliżu.'), hence you need to use a preposition 'near' instead of 'nearby' in that sentence
2) I'd rather write 'I would like you to come and stay at my house for about 3 months, if you will/would agree to.'
3) 'This would be a trip or holidays rather than a job'
4) ...who speaks {a} foreign language...
Except for 1 and 4, the sentences by you are OK, but seem to me (only me)a bit confused.