| Var Sardos |
Okay, all spells list how many actions it takes to cast them. (Some spells are cast as reactions or free actions, but those, by the nature of being a reaction or free action, don't interfere with normal movement.)
All characters, by default, have 3 actions each turn to move, cast spells, attack, interact with objects, whatever.
So, if a character has a speed of 25 feet, they could use all three actions on their turn to move up 75 feet (25 * 3), or they could use two actions to move 50 feet and cast a 1-action spell, or they could move 25 feet and use a 2-action spell, or not move at all and cast a 3-action spell.