Its all set and setting. LSD will effect everyone different. The first time I tried LSD I was alone and took 200mcg, halfway thru I had a "bad trip". Only one Ive ever had and I love LSD. I wouldnt say it is TOO euphoric. Its just stunning. Visuals, time distortion, your mind basically unchained. youll get some bodily sensations also.
My only advise is start with 100mcg for first trip. Trip sittter isnt necessary in my opinion if you're comfortable being alone in general. Have fun, be safe!
Edit: Also if youre a cannabis smoker id stay away until the comedown on your first trip. Cannabis can really make LSD take off quick lol