For your first event:
It's JCF event on the 3rd, 4th and 5th floor of a ferry terminal in Kanagawa from 11am to 6pm.
Cosplayers must pay a fee of 1500 yen (if you're a recipient of JCF's mail magazine, it's 1000 yen). Non-cosplayers must pay 2000 yen (1500 if you get the magazine)
Directions ~ From Tokyo Station: take the 八重洲口 exit and catch a bus in front of 「月島」 station. The bus will be bound for 『晴海埠頭』. Ride it all the way to the last stop and get off there.
(If you want to read the place names ~ plug them into your seach engine and see what pops up, or ask a Japanese person or local to help you our. Decoding readings for names isn't my strong suit ~ I don't want to give you bad information.)
All other details are to be announced closer to the event.
For your second event: http://www5c.biglobe.ne.jp/~yuusya/yomi.htm
, this might be difficult for a Tokyo-newbie to get to. If you do end up attending, you may want to leave for the event a bit earlier than you normally would to make up some time in the event you get lost or miss a stop and have to backtrack. It's well outside of the main Tokyo metropolis requires a few train transfers (someon non-JR-trains) to reach. The main line serving the area seems to be the KEIO.
KEIO line map
The station you want to end up at is ~ 京王よみうりラン KEIO Yomiuri Land. If you're staying within the city ~ your easiest transfer from JR is probably at Shinjuku station. You won't be able to use a rail or commuting pass on the KEIO line though and will need to exit the JR station area to reach the KEIO one. There should be plenty of signs in English, but the station is pretty big, so you might just want to ask someone to point the way.
The event runs from 10:00am~4:00pm
The event fee is 1500 reguardless of whether or not you cosplay.
All genres welcome, no military costumes.
You can bring props like beachballs, as long as you don't bug the people around you with them.
Please change into and out of your costume at the event.