As Bogey said before, its best to ask your local surfboard dealer and see what they think. Be honest about your ability and experience. I see too many people that cant surf and will never learn to surf properly simply because they are riding a board that is not suitable to their weight, height or skill level.
Heres a little bit of help for you anyway, just a few examples.
Height in CMS to what kind of Starter board you would probably need, for two to five foot surf. These are probablys and not definitleys, because its still best to check em out yourself with your dealer.
Someone 150 CMS would want something around 5'8 and up
160 CMS would want something around 6'2 and up
170 CMS would want something around 6'6 and up
180 CMS would want something around 6'10 amd up
190 CMS would want something around 7,2 and up
200 CMS would want something around 7,6 and up
Your weight is the most important issue, if you are too heavy for a certain board, it will sink when you stand on it.
When learning its best to use a board about 2.5 Inches thick and about 21 Inches Wide.
As said before Fun Boards are pretty good for people startin out, get an NSP board or something like that.
Hope this helps you out. Have fun.