dead trees are more dangerous as they get brittle and can both drop limbs and snap the hinge very easily. mind how you go.
If you want to do tree work don’t get a little home owner saw, spend the extra on a pro model saw. Something like 50ccand a 15″ bar will do a great deal. Do your course first, and you’ll get the chance to use one or 2 and pick the brains of the instructors.
Stihl are not better than husky, both a great, so is echo, or dolmar/makita or jonsered. consider who your local dealer is and what they sell…if you can’t get a saw fixed you’ll hate it.
if you want better tips get on arbtalk, opefourm or arboristsite. the last 2 are primarily american but much more active than arbtalk.