I cannot figure out what travel website I was on when I questioned about getting a train ticket from Southampton to York. The overall advise was (after disembarking the ship) to take a train from Southampton with a stop in Oxford and avoid Crosscountry trains. I am also not willing to go through London. My son and I haven't ridden a train before, and I really want it to work well.

I found a way I could book on LNER website for l0:15 a.m. -ll:38 a.m. Southampton to Oxford and l2:11 p.m.-15:20p.m. Oxford to York. Even if I try on the LNER website for a ticket from Southampton to York as one ticket and choose "via" Oxford (to force the stop to be in Oxford), it will not do it. If I need to buy two tickets, I feel like maybe i should do the 9:15-10:39 Southampton to Oxford and then l2:ll-15:20 Oxford to York to make sure I don't miss the second leg. It sounds a lot less stressful if buying two tickets instead of one ticket with a stop in Oxford. Hopefully, you can tell what I am asking.

Do you want to change trains in Oxford or are you just following advice to do so? If you want just one change I’m finding that when I search Southampton to York on nationalrail.co.uk the journeys with 1 change do so at Birmingham New Street. Journeys with more changes take you through London. Personally I’d opt for the 1 change in Birmingham. On 1 ticket. I find the National Rail website easy to use.

There's a lot of useful information on the Seat61 website. Also worth checking the Trainline website for journey options. I've booked a fair bit on the Trainline website and found it user friendly. Booking direct with the individual rail company would also have advantages.

Cross Country is fine. I use it regularly.

OK I was just following other advice that the easiest place to change was Oxford and to avoid Cross Country trains if at all possible. This is great to hear. I figured maybe I am over worrying about things. I was definitely only wanting one change.

https://www.nationalrail.co.uk/ has a "route options" just below the trip booking fields

I was excited to ride a train, but there is so much to take into consideration. I spent hours yesterday deciding on two seats. I am not even sure if we are going frontward or backwards. It was a different train than this route, and the diagram wasn't marked. With half the train riding backwards, I figured it might not be that bad. I was trying to pick seats where suitcases wouldn't be stolen. I way overthought it. The suitcases are small-- like 20 inch roll ons, so they will go overhead, and I will be on ALERT with my eyes glued on the compartment up and above across from our row where I hope to put them. It must be difficult to relax and enjoy the train when you are on high alert. Hopefully, the chances are quite slim on all trains.

I think today I will make the decision and get these tickets. The seat will be the hardest decision. Plus, I want a long wait so I can figure out where to go to get the next train. Suitcases will be very light, so they will be easy to lift. If there is a "major disruption" in our journey, which I see the words at times for some train journeys, then do we just try to get to the transfer station if possible and worry about it then? For example, if we did Birmingham New Street, and there was a disruption of BNS to York, how do we get out of BNS? Kudos to all of you for understanding mass transit.

I think you are looking at a European transport solution with a North American mind. I've only once seen something stolen from a train rack (at the end of most carriages) or in the overhead, or sometimes between seats (where backwards seats meet forwards facing seats) and the guy was caught in seconds.

Major disruptions.... Well the train guard will tell you what to do, they will talk you through minor and major issues, in fact you may become bored to know that you are waiting for a platform to clear etc etc. Assuming you don't understand the advice ( for any reason) you will find yourself surrounded by a bunch of people who do understand, so just ask your fellow passengers. You will find that asking for advice brings out the best in Brits.

All in all, over thinking is not your friend here.

Birmingham New Street is not complicated, it is just big and you cannot see it as the platforms are underneath the station. Look for signs (everywhere) and just do what they say.

One thing that may knock your plans is that reservations sometimes get ruined (eg a different train is used), don't panic. We are all adults.
If you find someone in your seat, again don't panic just 1) check it really is your seat and 2) ask them to vacate, phrased like "excuse me but I think you might be in my seat" is better than "shift it buster".

Over thinking is my super power. I did laugh at your reference to my North American frame of mind. Yes, I have never ridden a public bus or train, but I literally just finished booking everything. I was hoping crime is overstated when you Google. It would be exhausting to be on high alert the entire time. I have the most chill teenager in the world. He does not worry. We will make lemonade out of lemons if need be. I took the 10:15 a.m. train so if the ship is late, I don't have the overwhelming urge to jump over and swim so I don't miss my train. Sorry if sarcasm is lost in translation. I am super excited. My son has no idea. He thinks we are going on a typical long road trip in the U.S., but he loves surprises. Getting the final details booked is a great feeling.

Most trains will have a coffee trolley which goes through once if the journey is at least one hour long. It will be expensive and not great. But sometimes they forget to load water at which point tough luck. Don't be surprised there will be booze probably and chocolate.

Station concourses also should have fast action cafes. Look out for "Meal Deals" which offers a combo of food and drinks at more reasonable prices. Mainly focus on cake,sandwiches and tea/coffee.

Have fun

This is all exciting.