Goggle Wearing Newbie

Last night I bought swimming goggles. They worked really well except I had them on too tight and didnt realize it till I was finished swimming and looked at myself in the change room. It looked like I had hickies around my eyes. It looked terrible! And I had just said goodbye to the other swimmers not knowing I had these big red circles around these big puffy eyes. What a newbie. Anyways....I had a good swim but I definately need to practice alot. I do two lengths of front crawl and need to take a break. I need to be able to swim continuously for 40 lengths. I have to swim 750 m at the triathlon which is approximately 30 lengths. I am far from that. I have to be able to swim relaxed. Well practice makes perfect.