Gear recomendation?

I have my first trial training session at a boxing club in two weeks. The club told me they can lend me gloves and other equipment temporarily. However, since I know this will be a long-term hobby for me, I'd like to buy and use my own equipment from the start. I've never done this sport before, so I'm not really familiar with it. Therefore, I'd like to ask you what equipment I should buy (gloves, wrap, mouthguard, and possibly headgear). Which brands are good? I also have a question about weight. I've seen that there are different weight classes, such as 16 oz, 14 oz, or 12 oz. What's the difference besides weight? Why would you use heavier gloves? And what do I absolutely need? I've heard 16-inch gloves are necessary for sparring, and that you can also choose a different weight for the punching bag and for competitions. Thanks