@Ashley Wolfe
First off, the biggest win is that you are looking reinvest the earnings from your last deal. You need to decide where you spend your money based off of your goals, but I would definitely set aside some of the profits to work on education. Invest in yourself early.
All of my answers should be vetted by a professional...but I'm trying my best.
It is not necessary to form an LLC to do a lot of REI business activities. If you are purchasing another rental, I would establish that rental in an LLC. If you are serious about REI, I would also recommend getting it set up early to start building your "brand" and add credibility. This also depends on how active/passive you are....
A trust is not redundant and you need to discuss with your lawyer, who you need to seek out sooner than later. Most people wait until they exceed a couple of million dollars to establish trusts, but there is pros to doing it sooner.
Money in the bank is important, so are IRAs, college-funds, diversification, paying down debt, etc. (and of course, real estate)
If you have large taxable income, then the tax advantages of actively investing could be much more beneficial. However, for most beginners (or average people), I think tax advantages should be seen as icing on the cake, not the primary reason to invest.
At this stage, Ashley, I would focus on finding trusted partners and building the team out. Networking and educating. Surround yourself with really smart professionals, and you will do well.