Welcome Frank , and as to the detector ? Well I would say buy the best one you can afford if you think you are going to stay with this hobby, and most do as it is very fun .
The type ? That is something that you are going to have to search out . Go to the sites and read about all the types there are and what they will do.
Also in this site there is a page with all or most of the brands out , read what is in there and ask questions.
There is no perfect machine to detect with but they for the most part work well.
Right now the E-Trac by Minelab is one of the hottest ones out , and the V3I by Whites .
Quite a few are buying the Garrett AT Pro , that machine is water proof to ten feet and people are getting a lot of great finds with that one also.
I like the Minelab X-Terra 705 as it is a Coin / Relic , and Gold machine . You need to read up on it .
So as you see their are good machines out by many companies that would work well for you . Just have to see what you want.
And in the classifieds here on this site , many users have some very good used machines for sale , if you would want to go that route.
Have fun with what every you buy that is the main thing.
HH