Hi EndEz!
I have a word of warning for you: if you really want to win as many games as possible, you should keep in mind that Saim-Hann in terms of rules is the least competitive Craftworld of all 5. If you want to play Saim-Hann competitively you pretty much have to mass Shining Spears (and by massing I mean something at least about 3 units of 6 or 2 units of 9). The CWE codex supports other strong builds and technically you can use any of those builds with Saim-Hann craftworld - it's just that the Saim-Hann rules won't be helping you much.
Anyway, when building an army, ideally you need to make sure that you have at least the following three bases covered:
1)
Anti-tank: a good army should be able to destroy heavy multi-wound targets like vehicles or monsters. I'd say your anti-tank is ok if your army can reliably destroy at least one heavy tank/monster per shooting phase.
2)
Anti-infantry: a good army should also be able to efficiently grind through dozens of cheap 1-wound infantry models. I'd say your anti-infantry is ok if your army can reliably kill at least about 20 to 30 light infantry models per shooting phase.
3)
Command points: a good army should start with a healthy amount of Command points, because you need them to use Stratagems and Stratagems can make a world of difference in many tight situations. I'd say you need at least 8 CP in games up to 1750 points and at least 9-10 CP above that.
Now, with that in mind, here's a rough evaluation of units in the codex in terms of their practical efficiency.
1. Flexible/Multi-purpose/Support unitsGood/Excellent: Farseers, Spiritseers, Warlocks, Shining Spears, Dark Reapers (exarch should have a Tempest Launcher), Wave Serpents, Hemlock Wraithfighters
Average (which means not too powerful but still playable):Autarchs, Wraithguard with D-scythes, maybe Wraithblades, Fire Prisms (only if you take at least TWO of them to use the "Linked Fire" stratagem, preferably three), Wraithlords (only if taken as Iyanden!).
2. Specialized anti-infantry unitsGood/Excellent: Defender Guardians, Swooping Hawks
Average:Dire Avengers, Windriders with scatter lasers (only if taken as Saim-Hann!)
3. Specialized anti-tank unitsGood/Excellent: Crimson Hunters
Average:Fire Dragons
Please note that I didn't evaluate any named characters - some of them aren't bad, but using them is really a matter of personal taste.
Apart from that, basically, any units not listed above are either mediocre or bad - which means that you'll basically weaken your army by taking them.
Also please note that units listed in the first section ("1. Flexible/Multi-purpose/Support units") are there because they can do reasonably well in both anti-infantry and anti-tank areas, while characters listed there are good at assisting the rest of the army in dealing with all kinds of targets.
Hope this helps, good luck with your first battles
P.S.
If you don't mind me asking, does Ramadan prohibit from visiting other people's homes, or from playing games...?