Just went back to back on first two AG batches

Depends on your style of beer to a degree. I tend to always mash out but many homebrewers don't. Suggest you try a few batches with and without and compare results. Here's what the pros say on the subject: https://byo.com/article/lautering-1... is most important,steps to occur more easily.

The thermapen (from Thermoworks) is considered a top level thermo, cost is about a hundred bucks. In my experience the economy models from Thermoworks are just as accurate for about 1/3 the price, they just take a little longer to respond. I always have a backup thermo around. I would avoid infrared.

A cheesecloth is just fine for lautering. Ideally you'll filter the grain through a false bottom or bazooka wire mesh (probably easiest for small quantities). In addition to having a filter in the mash tun I use a fine mesh strainer. The goal here is to keep the grain out of the kettle, anything that accomplishes that should give good results.

With AG you have some serious control about what goes into the brew, that's the fun part. If you stick with it you'll be doing your own recipe creation . . . the sky's the limit here. Also, you can "break some rules" along the way, sometimes with seriously good results.

 

For BIAB, I would recommend using The Brew Bag. It's very versatile and has just the right mesh size for filtering out the grain. It can also handle very high temperatures (you can easily boil with it), and is easy to clean and dry (it doesn't absorb moisture). It's a very worthwhile investment, and no secondary filter is needed. (I even know someone who regularly uses it in a Fermzilla rather than the grain basket ("pipe") that is included with it. This also allows him to brew slightly larger volumes, and helps avoid stuck mashes).

https://www.brewinabag.com/

Definitely don't use an infrared thermometer as it can read the steam coming from the water/wort rather than the water/wort itself. I have often noticed quite a difference between the temperature of an infrared theormomenter and a digital themometer.