most asians are trained & used to sitting on the floor. Thus, no difficulty in 'seiza'.

1] A very beginner like you, bear the pain if possible as long as you could. When unbearable, be at ease & relax ur legs. Do not stand up..sit at a position which is comfortable for you. However, you feet must not be shown infront towards sensei - consider disrespectful. Hmm? ii dontt know to explain this. Keep practise your seiza...eventually...will withstand longer. Prolly 1-2years for fully 1-2hr seiza. However, when grading..you will seiza more than 2hrs. It's the painful & crampful time - for those who are not to use to long seiza.

2] Need not to buy 'shinai' or 'hakama' yet (beginner set) -- REASON below.
COLOURS:
- Dark Blue (male)
*- White(Gi)-Black(Hakama) [Not really recommended for male unless you're in Dan-level, female is okay)
*- White gi-hakama (Female only).
[* = new rule if not mistaken]

There was once a conflict between Japan-kendo & Korean-kendo (Kumdo). Thus this why the rule has implement. That's what ii heard.

R: Get to feel the kendo atmosphere..if you're really into it. Then you may start thinking about buying it. When mastered the very basic etiquette of kendo, then probably you'll - start thinking or buying/rent - need your own "Armour" - which are costly. DO NOT SIMPLY PURCHASE KENDO EQUIPMENT ONLINE - CHECK PROPERLY BEFORE PURCHASE ANY.

Shinai = bamboo stick sword. (~$10-20)
Gi-Hakama = the uniform (~$50-70)
Armour = (~$300-1,500) *subject to some materials are expensive*
[Price approximation in USD/UK dollar]

3] SCORE - the 'Shinpan'(referee) of three have to agree on each other (of two) that they see a proper strike & whom got the first hit. If one did not see, he can't give a point although other Shinpan saw a good cut & the kendoka should deserved a point. To avoid contradiction, the shinpan must be a really dedicated person & alert all the time. Thus, rarely this case occur - perhaps.

"Ki-Ken-Tai ichi" = Ki-ai + Ken + Tai...have to be syncronize as one. It's the basic step, and it's not that easy as you think.
"Kiai" = Battle-cry
"Ken" = Strike
"Tai" = Stomp? Or Movement.
This could be a reason that kendoka didnt get a point although he perform nicely cut. No Ki-ai indicate no energy on striking (applying in a real sword battle). They have to show all this 3-criteria during the sparring to get a point.

STORY: imagine this..in situation of war...no samurai kill each other silently. They scream or shout (the battlecry) gave them some sort of 'extra' energy & power to slash. That's the time when you see two groups of enemy run toward each other, shouting "HYAAAAA....!"

Further INFO - is better to ask your senpai. Cuz ii cant give exact explanation if the etiquette & rules are different. Check if your country is recognized under KENDO FEDERATION...if yes, thus no problem & usually has the same etiquette.