Deanna Said:

How do i start learning to write proper english.?

We Answered:

Even native speakers sometimes don't know how to write properly if they ignore writings skills, if they don't have a vast vocabulary, if they did not study.

Get a good grammar book with exercises and answers, get a writing skill text with exercises (if possible, with answers)or ask someone to correct them. Pay a tutor.

Here on the internet you can find free courses about how to write essays. Reading all kind of literature and using a dictionary helps a lot.

I'm foreigner and I did the Proficiency Cambridge Exam when I was 48, I got a B+, if I could you too.
English Grammar is not as hard as Spanish Grammar, English vocabulary is not as huge as Spanish but writing reports, letters, informs, giving instructions, writing essays, etc, have the same rules.
Go for it, improve your skills!

Ron Said:

Should my children learn to read and write english before learning another language?

We Answered:

It is much easier for children to learn new languages because they absorb so much more than the average adult. Chances are if they are speaking English with you at home, watching TV, and interacting with other English-speaking friends, they are getting adequate exposure to English. You may have to take extra steps and help them to practice reading and writing in English. The good thing is that the alphabet is the same, so that will make it a little easier on you. However, if you don't have time to do this, then maybe an all-French school isn't the right answer. There are other opportunities available that would allow them to learn English and another language at the same time. Plus, if you don't have the time to learn French yourself, then like you said, you wouldn't be able to help them out with their school work.