I've been crocheting for about 20 years now (gah, now doesn't that just make me sound old). May I suggest a beginning project of washcloths or dishcloths? If the come out less than perfect, who's going to care or even see except you. You will also have the added benefit of having a small project and the results will be immediately useful. Just get some cotton yard and an H hook.
There are many videos on youtube showing how to do the different stitches. I have really learned a lot from a lady named Teresa that posts videos there. Start simple...the single crochet and the double crochet stitches.
Do a washcloth in single crochet, another in double crochet, and then do your next in a combo of the two stitches. Do these over and over until you feel that the stitches have been reinforced in your memory - then find a new stitch to try.
The tension will come with time and practice. Just keep working at it and you'll get it. You may need to adjust the way you hold your hook and yarn in a way that is better for you. There is no right or wrong way to do it, just whatever works best.
Good luck to you - and remember when you get frustrated...it's supposed to be fun. LOL
