Well, if the uid is a numeric datatype, you could use:

SELECT COUNT(uid) FROM tracking WHERE uid = $trackuid

If not numeric, you'll have to surround with quotes:

SELECT COUNT(uid) FROM...

I will restrain from lecturing on normalization (http://dev.mysql.com/tech-resources/articles/intro-to-normalization.html). I assume you've probably never heard of it but I'd highly recommend looking...

Count is an aggregate function. It's not going to return anything from the database. It's only going to count the number of records matching your criteria and return the total.

You could start off with basic data validation. Pumping all of the fields into the db without checking even one of them? That's just asking for injection.

Post the code and error messages.

Do you have phpmyadmin? If so, create a table with the appropriate rows, save the excel file as a csv, and import to the table.

Yes, the best way is to just save the image path. You can save the image into the database as a blob but, most say it's a bad idea. Have a read here (http://www.phpriot.com/articles/images-in-mysql)...

Glad to hear

Datetime is in the YYYY-MM-DD HH:MM:SS format so, Friday, August 28, 2015 at 8:00PM would be:
2015-08-28 20:00:00

Yes, Oracle is a beast and a memory hog. My favorite comparison was made by Charles Phillips, President of Oracle:
"We're both in the transportation business," Mr Phillips said. "We have a 747, and...

You shouldn't compare the two. It's like comparing a school bus (Oracle) to a Corvette (MySql). Oracle can deliver tons of data in a reasonable amount of time consistently. MySql can deliver smaller...

Could be wrong but I think this will require some type of middleware like PHP to communicate between them.