The usual (and almost always correct) advice for a beginner level surfer is a long board that is around 9ft long, 22 inches wide and (given your size) 2 5/8 thick. You can go very slightly smaller on length and width, but can also go bigger (probably wouldnt go past 9'6); dont go thinner.
This provides you with a board that is easier to paddle, easier to catch waves and has a big margin for error (pop up speed and timing, foot placement etc). You can't duck dive it, but you wont be able to surf a board you can duck dive anyway. So this maximises your time in the water (before you get exhausted) and your ability to catch waves. If you cant catch waves, you know its you not the board (which is fine, of course you need to develop the skills)
The above measurements are a pretty standard longboard length so there are many many options. As to materials, epoxy is tougher so perhaps better for a beginner, but a standard PU is perfectly fine (
http://www.boardcave.com/the-surfers-co ... e-is-best/ ). Second hand is ideal, if you can find one. Three fins rather than a single fin; dont go for a board that is designed as a nose rider. Just a regular all round longboard is what you want.
Dont stress too much about your first board. Its a learning board, it will get dinged, it may not be a board you keep for more than a year (depending on how often you surf); its a board for you to get some skills and start learning what works and doesnt work for you in terms of surf equipment. Just make sure its big enough and in good condition.