No problem but what are your questions?

As in this case, when I'm going to book seats from Amsterdam to London I don't know which option to book, which is the best option? follow a print

another problem i encounter is i can't access the eurail website

Eurostar can be booked via Eurail; there's an additional 2€ booking fee.

I'm not sure what's wrong because I can get to the booking website.

the problem is that when I go to book on Eurail this appears.

You are trying to make a reservation tomorrow.  Have you activated your pass? In that case, what is start date of the validity period? 

You will not find any seats for 1 day later-there is on THIS train also a small quota they sell to passholders. MAYbe, maybe, you can still find seats from BRUssel and then use normal hourly slower train (NO RES even possible) to reach BRU=be there at least 35 mins before dep. time for all the airline-imitation checks they like to do

My trip will be on 06/30/2022, how do I know I activated my pass for that date? now when i book, it loads infinitely

My trip will be on 06/30/2022, how do I know I activated my pass for that date?

You can check that in the app. You don't need to activate though to make a reservation. But if you do activate, then you need to search on a date for which your pass wil be valid.

now when i book, it loads infinitely

That means it is very busy. Usually in the evening. Try again later.

I had a 1st class paper Global Pass that expired in November 2022.

I have purchased a new identical paper Global Pass that I intend to use from September 2023.  It arrived promptly in the mail.

I have created a new ‘trip’ with my details, but have deliberately not selected a ‘start date’ to keep it flexible in case of (unlikely) last minute cancellation being required, or flight delays from Australia.

However when I try to make reservations, I receive the infuriating ‘your Pass isn’t valid on this date’.

Is this because despite me creating a new (undated) “trip”, the site believes I am illegally trying to reactivate last year’s pass?

I successfully made a Eurostar reservation via the Belgian Railways b-europe site as bookings open six months before, and am cognisant that (for instance) TGV reservations France to Italy aren’t available on b-europe.com until four months before.  However I’d like to see how good pass availability is, and so would like to insert a ‘ghost’ date, but eurail.com won’t even let me do that.

How can I achieve the latter?

If you had a pass earlier, then it's possible that, when you go to the Eurail website, it automatically selects the older trip with the older pass attached.

You should be able to select your trip on the reservations page. If that doesn’t work anymore because of the error message, then log out and then log in again. When going to reservations, it should offer to choose your trip. If that still doesn't offer a trip selection, then delete browser cache and cookies for eurail.com and try again.

You can also book seats elsewhere of course. That can be cheaper.