here is are the notes so far( i did them rather quickly) but included everything I hope!

Lets take an example:

going down group 2,

as we go down from, from Be to Ra, there is a general increase in electrons, as a results the number of shells will increase(since more shells are required to hold the electrons).

However as the number of shells increases, there is more electron shielding- more repulsion between inner shell electrons, and this pushes the outer shell electrons futher away from the nucleus, resulting in the outer shell electrons experiencing less nuclear attraction. Although, the number of protons increases, this is outweighed by the increase in atomic radius(distance from nucleus to outer shell electrons- resulting in less nuclear attraction(attraction from protons)), and electron shielding.

Now lets take a look at the elements in period 2, from Li to Ne.

As you go across this period, the number of electrons in the outer shell increases by one. So since no new shells are being added, there is no gain in electron shielding, so across a period the electron shielding does not Increase, also since the number of electrons increases so does the number of protons(since the atomic number increases by one as you go across the period). So this results in more nuclear attraction from the positive nucleus on the outer shell electrons, and this draws the outer sell inwards slightly, resulting in a reduction in the atomic radius(distance from nucleus to outer shell electrons), since the outer shell is drawn inwards slightly.

Note: Up to element number 20, electron configuration changes slightly, since the outer shells can hold more than 8 electrons. What I mean is that, you will have to account of the subshells and atomic orbitals. for example the element with atomic number 30, will have this electron configuration:

1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10

Now here is a little trick:

The shells usually get filled in order of increasing energy level, so you naturally would expect the 4th shell to have a higher energy level than the third shell(which contains the subshells, (3s2,3p6,3d10)), and actually it does, but this occurs when the 4s subshell is full(i.e. contains the 2 electrons to fill it up)

so we should actually write this electron configuration as:

1s2,2s2,2p6,3s2,3p6,3d10,4s2

but the 4s subshell gets filled before the 3d subshell. But when it is full then it has a higher energy level than the 3d subshell.