Questions about visiting Osaka

I have booked for Osaka Japan in Jan 7th, be arriving on the 9th.

Do I need to purchase Japan rail pass before I get to Japan? I�fm just worried about scammers or going to wrong site that�fll scam me.

Do I need to have a tour guide for Osaka castle? Could I take pictures inside the castle?

Can I take pictures inside the science museum?

What would you think is a minimum budget for a week in Osaka? Of course I would be visiting Kyoto for one day for the railway museum and Kyoto tower and another day in Hiroshima for the peace memorial.
I�fm looking at at least USD 350. That�fs just my guess, it can be smaller than that.

Do I need to purchase for shinkansen trip to Kyoto from Osaka and Hiroshima from Osaka before I get to Japan?

Would I be able to get some help from someone when I first arrive to Japan? I�fm still learning the language and I can read hiragana and katagana, but I�fm still a novice.

Do I need to purchase Japan rail pass before I get to Japan? I�fm just worried about scammers or going to wrong site that�fll scam me.

Do you need to purchase the Japan Rail Pass (nation wide)? If your destinations are Osaka, Kyoto and Hiroshima within 5-7 days, Kansai Hiroshima Area Pass (5 days) or Sany0 San'in Area Pass are cheaper and appropriate.

https://www.westjr.co.jp/global/en/ticket/pass/

Do I need to have a tour guide for Osaka castle? Could I take pictures inside the castle?

Well, it might be better to go with tour guide, but most people will go by themselves. You can rent audio guide at the information office (1F and 5F).

Can I take pictures inside the science museum?

It depends on the specific places. There should be "photography is prohibited" sign if it is prohibited.

What would you think is a minimum budget for a week in Osaka?
I�fm looking at at least USD 350.

Do you mean for meal? Then yes, it would be sufficient. Of course you can spend for more if you eat luxurious meals.

Do I need to purchase for shinkansen trip to Kyoto from Osaka and Hiroshima from Osaka before I get to Japan?

No, you can buy train tickets on site. As noted some rail pass will save some money. These passes are cheaper when you buy them outside of Japan.

Would I be able to get some help from someone when I first arrive to Japan? I�fm still learning the language and I can read hiragana and katagana, but I�fm still a novice.

Most of the touristic places (like Airport) have "Information center". Don't be afraid, Japanese people are not so different from people in the US. Be polite and respectful, then you should be fine.

Just to add. that you will be fine. A friend of mine (rollercoaster nut) visited knowing only the Japanese for Man, woman, entrance, exit, chicken, pork & beef and she had a fantastic time

Your English is fine. Which means you'll function in Japan just fine. 95% of Japan has some form of English signage for everything.

After coming to osaka, you must visit for few days.you can buy osaka bus and subway pass =800 yen,weekends =600 yen
Hankai tram 1 day pass=600 yen1 way:210yen
Nankai bus pass whole line=1050 yen
Osaka city bus 1 day pass=500 yen
Osaka amazing pass=2800, 3600 yen(1,2 day)