[gchappel]

Computers are a "nice" thing to have, but certainly not needed. I know several very good riders that do not use them. For beginning training, I would find a heart rate monitor much more useful than a bike computer. If you want to track distance use an app like strava on your phone.
I found tubeless tires a mixed blessing, on a road bike. Makes a much bigger difference on a mountain bike where low pressures can really make a positive difference. On the road bike it gave a slightly better ride. Flats seemed to be less common, but when you did flat it was a real pain. The tubeless tires can be more difficult to mount, repair and reseat on the rims when you are on the side of the road. For me it was not worth it and I went back to tubes for training.
Get some puncture resistant tires like gatorskins and go ride.
I do not think you mentioned lights. At least for training rides get a good flashing red rear light for each bike. A good one. Depending on where you ride, a bright flashing front white one may also be helpful. You can now be seen from space, but still 1/2 of the drivers will never see you.
Have fun
Gary