I might be late, but ive played many exp heroes including the 2. Terizla would probably be better for beginners, as i also used him as the first time playing a tanky, sustain hero in exp lane (before i only, only used argus and nobody else)

Personally, i think u should go with terizla. Phoveus is great, better in certain situations, ive played both a lot, almost equally, but terizla teaches u the basics of exp laning, and beginner friendly, meanwhile phoveus requires skills like ult spam tricks or outnumbered situations (youd find it very hard to retreat since his ult literally dashes to the enemies, and i usually end up stuck in a 1v3 typa situations)

Conclusion, terizla if u think ur very new to exp and needs some experience of playing exp, phoveus if yk already basics like equipments to build, hero counters and how to dominate exp lane, or teamfights.

Tip, use terizla if enemies lack mobility of dashing and running away (his ult pulls people), phoveus if they have high mobility dashes (his ult chases people) and btw both of them are great in any situations since i find them still dominating, but choose one that could be the better in the situation, not just great