Are we allowed to do everything like we would on weekdays, or do we have certain prohibitions similar to those of Shabbat and Yom Tov?
One may not perform work (melachah) on Chol Hamoed. Cleaning and cooking at home is allowed. Additionally, one may do any work that would protect him from loss. Meaning, if something were to otherwise break, he may do the work to repair it. Therefore, essential household repairs such as, plumbing, heating etc. are allowed on Chol Hamoed.
Would one be permitted to develop photos on Chol Hamoed? Would he be allowed to type on a computer without printing?
One should be stringent about developing photos. In regards to typing on a computer – it is permitted.
Are you allowed to wear Tefillin on Chol Hamoed?
No, because the very reason for our observance of the holiday is a sign representing our connection to G-d, therefore, therefore, t would be unnecessary to display the sign through Tefillin as well. Having said that, the holiday must therefore be observed in an optimal way.
Would one be allowed to purchase clothes on Chol Hamoed?
Yes – one may purchase new clothing on Chol Hamoed to be worn on the holiday, and even if there were special sales or promotions, he would be allowed to make the purchases during the holiday.