Is water on floor from pipes, plumbing?

Remodeling old bathroom, old rusted drain pipes were removed and installing new ABS pipes and also moving some of the fixtures around. The picture below is the new setup we want. The green walls in pic I have full access on attic and opened walls to work with for vent pipes. The yellow wall I have some access but difficult. The main house drain pipe is behind the bathroom and its a 3" ABS pipe about 15 feet from toilet. I'm just wondering what is the best way to route the drain pipes and location of vent pipes (I have a large crawlspace so easy to work with). The plumbing for water is pretty simple so I got that. Thanks!!

I realized that I probably posted this in the wrong plumbing forum. Please forgive the rookie mistake. Greetings. I am a new member who is an accountant by trade but I have lived through enough flooded basements to understand the importance of proper drainage. With that introduction, I wanted to describe a situation that I stumbled upon in my home, relative to a floor drain in my basement, to get the collective wisdom of this forum. I am not sure if this is normal or a budding problem that needs attention. My home was built in the 50’s and is located in a suburban area. We have city sewers, both storm and sanitary. All drains in my home go to the city sewer. We do not utilize a sump pump or anything tricky (septic, French drain, etc.). So far, everything with my plumbing is working properly. I have two drains in my basement floor. One is at the far end of the basement away from any appliances, laundry, etc. I have been using this floor drain to run a hose from a portable dehumidifier. I have been draining the dehumidifier this way for several months with no problem. Last weekend I discovered a puddle near this drain but it wasn’t clear if the drain had a problem or if the hose simply got dislodged and ran all over the place. After cleaning up the mess, I poured a couple of buckets of water into the floor drain and the water slowly disappeared. Here is the interesting part. The bottom of the drain is about 9” from the surface of the basement floor. The seems to be sediment in the bottom of the drain. I can put a long screwdriver in the drain and the tip of the screwdriver goes about an inch, maybe less, into the sand at the bottom of the drain. The other thing that is interesting is that I can’t find a pipe exiting the drain. When I fish around it seems like there is some sort of irregularity in the wall of the drain in the direction of the storm sewer but I haven’t been able to get a snake or anything else in this so I can’t be sure. I’m assuming that there is some type of trap involved but I can’t find the exit. The water is going somewhere but where and how? There is water about 4.5” from the bottom of the drain. I’m thinking that this is the natural water level with the trap. I am thinking that it might be worthwhile to remove the water and as much of the sediment as I can with a shop vac and see it that reveals anything. Thank you if you’ve made it this far. Based on what I described, does it sound like there is an issue or are things ok? We have had a ton of rain and not a drop of water in the basement so that is encouraging but where is this water draining to and why can’t I find an exit from the drain to the sewer? Thanks in advance for any insights you can offer.