Question about focus - finished trials, went to a city and grabbed some paranoid assasin quest

I probably wasn't prepared, had no idea what this entailed. When i got to the final boss it was the hardest fight I had to complete - i did it on first try thankfully but it was an unexpected situation and I wasn't prepared.

Should i stop doing these journey activities i encountered since im so new and just focus on getting duraluminum stuff? I'm just sitting down now to craft my first flyer - but i dont think im ready for the 2nd part of that (glutton) if it is as 'difficult' as the first part.