Beginner rig?

I went through this myself recently and had a beginner rig that served me well. however my philosophy coming out was I wished I had bought second hand better gear. you can outgrown beginner rigs much faster than you outgrow a beginner board. beginner rigs are good for the first season and then you will want to upgrade.
the difference I noticed going to better gear was stark - the beginner gear was in many conditions actually harder to sail as it was much more impacted by gusts, heavier and less 'tunable' to the conditions.

they have their place but if you are going to stick at it for more than one season I would go second hand ails like a NP Ryde, Gaastra Pilot or severne Gator as they are tougher, more forgiving and you wont out grow them

just my 2 cents anyway

Like what the other two said.

I would go secondhand and get a wave sail around the 4m2 to 5m2.

If you just want to play about in light winds then any second hand rig with a small sail will do. I have a learner board for adult friends/family in light winds < 10knots, I rig up a 20year old 4.2m2 wave sail and 20year old carbon mast 430mast and 5 year old alloy boom (worth $100 or less secondhand).

If your goal is to eventually get planning in stronger winds and progress to a smaller board etc, then you should plan for the future and get a rig (sail + mast + boom) that will last and become your high wind rig.

If planning for the future:

Get a 2 piece second hand mast 400cm long (this should fit a 4m to 5m sail). Masts come in standard diameter(SDM) and Reduced diameter(RDM), typically SDM for larger sails greater than 6m2 and RDM for sails less than 7m2 (between 6m & 7m people pick and chose). So for your first sail, get a RDM mast. Carbon content 80% or more for lightness (you will be up hauling out of the water lots). The way a mast bends are categorized as Hardtop OR constant curve OR flex top. Sails are designed to fit a particular mast bend (For best performance) Stick with same mast and sail manufacture of a similar vintage for best results, this can be hard/take time if buying on the secondhand market. If you have a look at the diagram on unifibre: www.unifiber.net/masts-selector you will get and idea of what bend a mast is (most are in the constant cure category) if you looking at what is for sale (note that bend curves for a manufacture can change from year to year). Note that a mast will last you for years if you look after it.

You will need a RDM mast base fit into your mast

For a boom, get as new as possible or even consider going brand new if it is an alloy boom - these tend corrode over the years and you can end up with a stuffed one if you are buying from someone you don't know. A stuffed boom will probably work ok for light winds and learning. But in strong winds it will most likely flex too much and eventually break on you. Secondhand Carbon booms are expensive, but carbon booms can last forever (one of mine is 21years old).

Make sure the boom can go short enough to fit your small sail yet long enough so you can use a larger sail in the future, but note that alloy booms should not be used at or near full extension). My boom goes from 160cm to 220 which is enough range for my 4.2 to 7.8m2 size sails. The boom will also need to the fit the RDM mast and ideally a SDM (for the future).

You can always post on here if you have questions on specific items and their compatibility etc.