I'm trying to get my first kerbal in orbit, but after a few dozen try I feel I do something wrong.

If I understood correctly, I need to be at >70km with a speed of nearly 3000 m/s, and both apsides up to 70 km. To do this, I tried the recommended method of being at 45deg east around 10000m then progressively get more angle to be a 0 around 70km, while managing speed to maintain my apoapsis up to 70km (and less than 80km ?) and bring the periapsis also up to 70km (shown as -70km in the ui).

Did I miss something here ?

I got many times in an «orbit» with both apsides up to 70km (81/-74, 88/-89 82/-85) … but with an orbital speed less than 2200m/s so the ship fall back on kerbin, and I often got seemingly correct speed, but with a shifted orbit (eg my last try where I got an apoapsis of 121 km and a periapsis of … -97km, causing my trajectories to go trough kerbin).

I'm in career mode, I'm using the swivel liquid engine for final maneuver, and I tried different builds but currently I'm using another swivel…