AQA AS Level Physics Equations Units?

Prolly a dumb question, but is does every equation we use have SI units ( or equivalent ) or do I have to learn units alongside the equations?

Not dumb at all.

Yes, for the questions asked in compliance with the exam specification, you will need to learn the units for the equations used.

Any physical property that can be measured, will have an SI unit determined by it's 'dimensions'.

There are seven SI base units which are all traceable back to an international reference standard:

Length = metre
Mass = kilogram
Time = second
Current = Ampere
Temperature = Kelvin
Amount of substance = mole
Luminous Intensity = candela

All of the variables in any equation must break down to one or a combination of the above quantities.

There are twenty two further 'derived units' which use the base unit descriptions in combinations and assigned additional names.

For instance:

Frequency = Hertz = 1/seconds
Angle = radians = circumference/diameter = metre/metre = ration = no dimension.

There are many other derived units and you will need to be able to break down the dimensions of each variable in order to verify that any given expression is homogenous. i.e. the dimensions on both sides of the equation are identical.

https://en.wikipedia.org/wiki/International_System_of_Units

https://en.wikipedia.org/wiki/SI_base_unit

https://en.wikipedia.org/wiki/SI_derived_unit

Oh right thanks, so for every equation involving mass the unit is kg, and for distance it is metres right? never cm or anything