One week to go before the first event of the season for us (Sprint Tri).
Welcome to [MENTION=370921]bfs2[/MENTION] and [MENTION=369822]SoCalRoadie[/MENTION] to the Clyde Tri herd.
bs2: Your times are completely reasonable, but don't forget transition times when you do your math. This will vary quite a bit by venue (depending how far the pool/lake is from the pit, your equipment, or if it's a wetsuit race, for example), but 3-5 minutes in T1 and 2-4 minutes in T2 are going to be common times.
The best advice I can give to first timers is to do what they call "bricks" as you lead up to the race. For me, that meant a quick sprint ride on the bike (7mi) and then a practice T2 in the garage followed by 1 to 1.5mi run. The muscles used for biking are similar but different than running; many guys get a rude awakening on race day. My first Tri, I ignored similar advice offered to me and on race day I walked the first bit of the run until my legs would work again. The next season, I did bricks.
Next best advice I can give is just to relax and have fun. Especially getting into the water, just try to relax and find your rhythm. Some folks try to swim at 150% effort, and panic in the first 100 yards when the thought HOLY CRAP I AM DOING A TRIATHLON sinks in. Don't freak out; flip on your back and kick for awhile, get your HR down, and then enjoy the rest of your race. You'll be fine.