Don't wait to find a worship place or isolated location to pray. He is everywhere and can listen anytime you want to connect to Him for your needs or otherwise. So whenever you need help just start praying, no matter even if you are at a public place and fear that people will be watching you.
Remember a right time for the prayer is when you feel a need inside for it and this is the time that your prayers are likely to be listened and accepted by God more than any other time. Although praying at an isolated place is good, it is not a prerequisite for acceptance of your prayers.
You do not need to make particular gesture, for example, raising of your hands. Just start prayer in your heart and God will know all you say in words or say in silence. He will listen to your prayers there and then and might accept them.
Although a minimum cleanliness is a standard requirement for prayers, do not worry if you are unable to find water or any other source of purifying yourself to an extent; you can still pray and there is no reason that merit of your prayers is affected. It is inside what you require and ask for that is the most important thing to God.
Prayers are a way of communicating directly with God, and for this you do not have to wait for a place and time. Since God is believed to be everywhere all the time, He waits for you to ask for your needs from Him, and you should not delay this matter.
Your intention is the most important thing in front of your God. If He feels you are genuinely interested in seeking His help, and consider Him the only one who can provide for all we need, then He does not care what you are wearing, what is your gesture and what are your words and how you pronounce them. You are connected to Him.
Do not let yourself imagine that someone might be watching you while praying because it will divert your attention and the merit of your prayers will be affected. Only care about God while praying to Him, and do not be concerned about what is happening around you.