The taxi will take you in from the North East and you miss it all. No problem. Might add 3 minutes to the trip. I know the hotel, its just a few hundred meters from the Fidesz Central Office LOL (google FIDESZ party). Use city taxi if you have no other preference. You can download their app or call them. (google City Taxi Budapest). But do call and dont just get one off the Taxi stand. You will get a taxi number or a lic plate number if you use the app and you go out to the stand and get in the right one.
Get off the train and face the front of the station (glass wall and big clock). Then look to your right, outside the wall on your right are the Taxi stands.... Find your car. With the app you can track where it is.
Interesting hotel choice, but the Ibis hotels are generally very good 3 star hotels. You will be riding the M1 metro a lot to get to the center of things so get your BudapestGO phone app.