Colombia is not spelt with a 'U'

Agreed; and on that point, “u” should actually be spelled “you.”

In addition, while ending a sentence with a proposition is arguably acceptable, it really is something one should strive to avoid.

Further, while not an absolute rule, firms generally prefer that you capitalize their trademarks if you are going to use them as verbs —e.g. “googling.” (Quite frankly, they would prefer you not use their trademarks as verbs in the first place since it weakens the trademark.)  Conversely, foreign words — like “gringos” — do not necessarily need to be capitalized. 

The verb “Google” generally requires an object.

Commas should be used before and after direct addresses to the reader/audience.

Don’t forget to use definite and indefinite articles before nouns when appropriate; but don’t use them when they are not required.

The first word in a sentence should be capitalized.

When two adjectives are strung together, they should be separated by a comma.  On the other hand, compound adjectives — such as “spanish speaking” — should be hyphenated (and “Spanish” should be capitalized).

Contractions —like “lets” and “dont” — require an apostrophe.

While starting a sentence with a conjunction is unusual (but not impermissible), keep in mind that a subordinate clause preceding an ordinate clause should be separated by a comma.  That goes even for sentences that do not begin with a conjunction.

Questions should end with a question mark.

Finally, while “more simple” is acceptable, many people find “simpler” to be preferable.

I could go on, but I have a match to watch.