In Patch 5.3, Blizzard introduced a matchmaking system which is designed to give each team an even number of healing classes. This isn't perfect, however, as a healer can decide not to heal or a non-healer can decide to heal. In a game where the amount of healers can significantly tip the match in your favor, you are still at the mercy of the other players.
Other than that, no, there's no evidence that there is any sort of matchmaking aside from level-based matchmaking (eg. level 90 players have their own bracket, 85-89 players have their own, etc.). The order that you queue for a battleground is roughly the order that you'll be placed into one. This can be seen when 40-man pre-made groups all queue for a battleground at the same time and make it in, together.
As a side note, you don't need to purchase PvP gear to be successful at PvP. Last time I played WoW, all players had a base resilience level regardless of whether they were in PvE or PvP gear and it was stated that later on in the season, PvE gear of high item levels would be similar to PvP of the same level (PvE gear was dynamically scaled-down based on how far into the season we were). So, if you just get a PvE set of similar item level, you should be fine.
If you are worried about dying a lot, that's the risk of going into a battleground, alone. I highly recommend finding a coordinated group of friends. The later you are into the season, they more likely geared PvPers are queuing up to ruin your day in order to quench their boredom with the lack of new content.
