Don't worry, your English is fine . I don't like to be too hard on people that are just starting modelling but I can try and help you. People just giving you positive comments all the time will not make you better so sometimes it's best to be cruel to be kind . Ok some pointers for you to improve:

1, The handle texture has not been unwrapped properly as it looks a little stretched.

2, The blade looks like it has not been skinned at all or the texture mesh has been scaled down too much over the texture.

You're doing pretty good when it comes to 'low poly'. Some people make models that are far too high poly but it seems like you understand how to make a model low poly .

Are you able to post two screenshots, a screenshot of the skin with the mesh unwrapped visible and a screenshot of the wireframe in 3d view? It will make it easier for me to see where you are going wrong.

I can't download your model because I'm on my brother's computer which does not have MED .

Will these textures be any help?

Texture 1
Texture 2
Texture 3

Texturing becomes difficult where metal is concered because shaders are required all depending on how much quality you want, but this is not up to the modeller. Ok lets a company hire you to do work for them:

They want a knife. You make them a knife. You ask them if they want shaders on the blade (metal part). If they say no, you have to obtain a photo of a knife blade with fake reflections. If you ask them if they want shaders on the blade (metal part) and they say yes, then 1 shade of grey like you've done is great . Verstehe?

Ok, as you used MS Paint, you can't be too hard on yourself, neither can I because skinning professionally using MS Paint is impossible . You need something simple to start off with. If I was you, get Ulead Photo Express. This is nice and simple and has most features you will need to get good skins.