Some suggestions. I rephrased since most of these are common expressions at least where I'm from (New York).

1. Don't take his words seriously , I think he was just kidding.
  - Don't take him seriously. He was probably just kidding around.

2. Something that you have done was totally wrong. You might need to adjust the way of doing it.
  This depends on context how I would phrase it.
  - Something went totally wrong. Try changing the way you are approaching it.
  - You did it wrong. You need to do this instead.
  - Something's not working, we need to adjust our approach. (Usually this is better, not saying "you" did something wrong, but displace the blame out to suggest a change in general.)

3. If I happened to bump my toes on a rock on a beach , I would cry like a baby if that happened.
  - I would cry like a baby if I hit my toes like that.
  - I would cry like a bitch if that happened. (Obviously more vulgar and only used with close friends informally... But it's the more common way I hear this phrase used.)
  (Usually I hear or use these phrases in response to something already in the conversation, so the subject is not repeated.)

3. I don't want to breath in people's smoke that is in the air , so I want to get out and get some fresh clear air instead of staying here.
  - I don't want to breath people's smoke (or second hand smoke) so I'd rather get out and have some fresh air than stay here.

4. Before you are quick to judge someone , you need to put yourself in his or her position. Maybe they had something happened to them the day before.
  - Don't judge until you've put yourself in their shoes.
  - Don't judge until you've walked in their shoes.
  - Maybe they had a bad day or something happened to them earlier.

5.. This phone is relatively cheaper if you buy it online instead of buying it at stores.
  - good!

6. I really hope that she would take took that into account that the fact that I did not mean to hurt her in any way.


7. I have looked through all the stores , but I couldn't find anything that I think he would like or that I can afford.
  - I have looked all over the place, but...
  - I have looked everywhere, but...
  - I looked through all the stores, but... (If you are referring to all the stores in a mall for example)
  Second part of phrase is good!

Please help me to correct these ! Thank you!

1. Don't take his words too seriously , I think he was just kidding.
2. Something that you have done was totally wrong. You might need to adjust the way of doing it.
3. If I happened to bump my toes on a rock on a beach , I would cry like a baby. if that happened.
3. I don't want to breath in people's smoke that is in the air , so I want to get out and get some fresh clear air instead of staying here.
4. Before you are quick to judge someone , you need to put yourself in his or her position. Maybe they had something happened to them the day before.
5.. This phone is relatively cheaper if you buy it online instead of buying it at stores.
6. I really hoped that she would take that into account that the fact that I did not mean to hurt her in any way.
7. I have looked through all the stores , but I couldn't find anything that I think he would like or that I can afford.

This is pretty good, just a few small things that I marked.

Please help me to correct these ! Thank you!

1. Don't take his words seriously, I think he was just kidding.
2. Something that you "have done"/did was totally wrong. You might need to adjust "your" way of doing it.
3. If I happened to "bump"(consider switching to "stub", as it puts more force behind the action) my toe on a rock on the beach , I would cry like a baby "if that happened"(you can take this out because you started with "if I happened").
3. I don't want to breath in "people's smoke that is in the air",(consider switching to "second-hand smoke" which is the term) so I want to get out and get some fresh air "instead of staying here" (I would remove this as it's already implied).
4. Before you are quick to judge someone, you need to put yourself in "his or her" (could switch to "their") position. "Maybe they"(could switch to "They might have") had something happen to them the day before.
5. This phone is relatively cheaper if you buy it online, instead of buying it in store.
6. I really hope "that she will" take into account "that the fact"(remove, as is unnecessary) that I did not mean to hurt her in any way.
7. I looked through all the stores but couldn't find anything that "I think"(could remove) he would like, that I can afford.