The New Zealander was drafted into the Faenza-based team after Daniel Ricciardo was injured in a crash at Zandvoort on Friday.
The soaking wet FP3 session was his first F1 track outing of 2023 and his first experience of F1's intermediate tyres, and after a steady start he survived a spin that saw him tap the nose of the car on the barrier.
He then ended up bottom of the order in 20th in the wet Q1 session, and thus didn’t progress to the dry latter stages of qualifying.
If it stays dry on Sunday, the race will see him log his first laps on slick tyres in the 2023 AlphaTauri.
"Obviously tomorrow it's looking potentially, if it's dry, I've got to relearn everything again, because I haven't driven in the dry,” he said.
“So it's going to be a very tough race. I'm excited. At the same time, I know it's going to be challenging, and I know we've got a lot to get through. So I think we're just after a clean race.
“The first half is going to be extremely tough, especially if it is dry. I'm going to be learning everything for that first part.
"I haven't even done any long runs or anything like that. So I don't know how the tyre performs. It's going to be a big learning curve.
"By the end of the race, hopefully I'm in a much more comfortable position with the car. That would definitely be the target."
Lawson admitted that things moved at a fast pace after Ricciardo injured his hand in Friday’s FP2 session.
"It was all very quick,” he said when asked by Autosport about how the weekend had developed. “I was in the Red Bull garage watching the session.
"And obviously, the crash, it was just a freak accident where it wasn't a big crash or anything like that, just the way the steering wheel flipped around.
“And it's never something you want to see. So firstly, I feel for Daniel. But I had the news that he had hurt his hands, so we went to the drivers' briefing as a sort of precaution. And then it was midway through the drivers' briefing, I got a message.
"I was very focused in on that second half of the drivers' briefing! Yeah, just a lot to take in, and realising that it was going be a huge amount of learning to do in the next sort of 24 hours."
Lawson already knew Zandvoort from last year’s F2 race, but his commitments in Japan meant that he wasn’t part of last week’s Red Bull and AlphaTauri preparations for Zandvoort in the Milton Keynes simulator, a task he performs for other venues.
"I was racing last weekend in Japan. So I flew straight here. Definitely would have loved to do more prep for this, especially the first couple of practice sessions, but obviously an opportunity like this is something that, for me, I waited my whole life for. So I take it with both hands and make the most out of it."
Lawson acknowledged that adapting to the F1 intermediate compound was the most difficult aspect of his first day in the car: "These conditions, getting the most out of the inter tyre – I haven't driven the inter before so that was probably the most challenging part about today."
“To be honest with how the first set of tyres was going [in Q1], I was actually feeling pretty comfortable. This morning was really tough.
“But yeah, as I said, I think the first run, we weren't too far off. And still improving. And then just the second set it rained again, and I expected it to get a bit slower, but obviously it didn't. So just getting used to this inter tyre, and these conditions."
Asked if he expected to be in the car for next week’s Italian GP he said: "I have no idea at this stage. Nothing is confirmed. Right now, I'm driving tomorrow. And that's all I know."
