Reserve a seat on a train from Amsterdam to Frankfurt

What is your date and time of travel?

Depending on your date and which train company you use, reservation might not be necessary.

Good information here. If you’re taking the direct ICE, you can make reservations via ÖBB. This is optional most of the year, but compulsory in summer.

https://www.seat61.com/interrail-and-eurail-reservations.htm#Netherlands

I will travel on May 12, on the page it appears that it is not necessary to make a reservation, but I am worried that I will not be able to board, and I don't know much English hehehe

Una reserva no es necesario, pero si quieres, es muy facile con el site ÖBB por €3.

https://shop.oebbtickets.at/en/ticket

Click ‘seat reservation only’.

Do you think that if it is necessary to reserve a seat, there are not always many people so that it fills up very quickly?

No, I don’t think it’s necessary. Especially for one person. There’s always space.

But it only costs €3. If you’re unsure, reserve.

12 May is on a Monday outside of any holidays. It should be OK, certainly if you're alone. A number of seats cannot be reserved (look for the “BahnBonus Status” seats, carriage number is visible in the DB Navigator app), so there are always some free seats.

Thank you very much for your response, one last question, I already bought my pass, I have not activated it yet, I will use it in May but I am already purchasing my seat reservations, when the day is ready I only activate the pass and I will be able to board the trains that I already reserved or should I carry out an additional process?

You have to activate the pass and also add every train you use. You can do that on the day you start your trip. If you like, you can also test or practice a bit, but be sure to choose a start date well in the future. And when you're done testing, cancel the pass activation until the day you start your trip. That minimises the chance on mistakes.

See this page:

https://www.eurail.com/en/eurail-passes/eurail-mobile-pass/getting-started

I bought a pass for 15 continuous days, I am afraid that I will activate it and lose it, but as I understand it, I can enter the option to activate it and enter the date of when my first trip will be

I bought a pass for 15 continuous days, I am afraid that I will activate it and lose it, but as I understand it, I can enter the option to activate it and enter the date of when my first trip will be

That is correct: you have to select the start date.

It's however not a good idea to activate it in advance. You can't cancel the activation once the validity period has started, so if something unexpected happens, e.g. you wake up ill on your planned start date, then it will be too late and you can't cancel anymore.

Sorry, could you explain to me how to add the trains I already booked to my trip?