Hi Yakfisher,
Nice to hear you're picking up freediving!
There is a lot of information on freediving suits here on Deeperblue, as you can imagine you're not the first beginner that arrived here on this wonderful forum asking for advice.
Use the easy 'search' functionality to find those "beginner freediving wetsuit" treads and read them through. Those will also help to develop your sense of what's important for your new suit.
In general I would advice beginners to go with a 5 millimetre freedive suit, with 'superstretch' nylon inner lining, hywa medium density neoprene and also nylon lining outside for most waters. This will be your sturdy comfortable suit allowing you to focus on learning freediving techniques first, without worry of damaging your suit. It also will do well for pool statics in 26c - 27c pools (most common competition pool temperature).
I need more information in order to be able to give you some better, more specific advice.
As of 'brands', I don't really care much about the names, but rather focus on the qualities I want to have I my suit. Being a mail man I need to very careful where I put my cash, I've not much 'room' for error so to speak
But if you've got close to a standard size, you're option is to go for a confection suit.
I suggest after reading through the deeperblue forum building up your understanding of freedive suits and your personal preferences, you thoroughly ask the shop what their options and differences are, explaining your needs. A good salesman would like you, a beginning freediver, to return to buy more equipment and thus provide you with some good options. But beware of the 'sharks' in for a quick buck.
I had good experiences with Elios, as well as my freediving friends.
Love, Courage and Water,
Kars
*Ps the suggested sturdy 5 millimetre can also be used for scuba, and you'll be surprised by the warmth and easiness of movement.