Proszę o sprawdzenie.

If we plan our Holiday we should be very carful, because is a lot of holidays troubles which wait for us. First of it could be travel sickness it’s uncomfortable special if our travel take a lot time. We should try to remember to take some pills with us! Second problem it may be lost our luggage or document – it’s one of the worst situation that could happen to you. You should go fast it could be possible to police office and report it. There are a lot of problems which could spoil our holidays for example: hotel doesn’t meet our expectations, terrible transport, …
To avoid it we must be really carful!

If we plan our 'Holiday' (dlaczego holiday duza litera?) we should be very 'carful' (blad ortog), because (brak słowa) 'is' (to ma się zgadzać z 'troubles'l.mn) a lot of 'holidays' (l. poj) troubles which 'wait for us' (lepiej 'await us').. First of 'it' (ale wcześniej pisalas 'troubles'-l. mn - dlaczego tutaj masz 'it') could be travel sickness, it’s uncomfortable 'special' (zla forma mowy) if our travel 'take' (zla forma tutaj 3os.l.poj-travel-it) a lot time.
THE second problem 'it' (niepotr) may be lost 'our' (niepotr) luggage or document – it’s one of the worst 'situation' (tu ma być l. mn bo wcześniej 'one of') that could happen to you. You should go (tu brak słowa) 'fast' (zle slowo i zla forma mowy) 'it' (zle slowo) 'could be' (wystarczy IS) possible to (brak przedimka) police 'office' (miejsce nazywamy 'station') and report it.
To avoid 'it' (dlaczego l. poj, jak mówisz o 'troubles?') we must be really 'carful!' (ortog)

If we plan our holiday we should be very careful, because there is a lot of holidays troubles which await us. First of all, it could be travel sickness, it's uncomfortable specially if our travel takes a lot time. The second problem may be lost luggage or documents - it's one of the worst situations that could happend to you. You should to go quickly as is possible to a police station and raport it. To avoid this we must be really careful.

... is a lot of troubles...= jest duzo klopotow, w polskim moze byc ale nie w ang - czasownik be musi byc w odpowiedniej formie