We are currently abroad for Pesach where things are much cheaper, and some stuff are of better quality than from where we live. So I have some questions regarding buying clothing during Sefirah:
1) Are we allowed to purchase clothing now to be worn after the Omer?
2) If current shoes aren’t comfortable, can new ones be purchased and worn in the Omer?
3) If it’s more convenient for clothes to be bought here, is that permitted?
4) Can new clothes be worn on Shabbos?
There is a Minhag* with sources in early Poskim to not buy clothing during Sefiras Haomer (except for Lag B’omer). However, in a pressing situation (i.e., where one will have a financial loss, or they will be uncomfortable until new clothing is bought) and one can’t wait until Shavuos, one may buy clothing during Sefira (however it is best if it is first worn on Shabbos or Lag B’omer).
All this applies to clothing that are considered ‘Choshuv.’ However, regarding clothing which are less significant, there is more room to be lenient.
And for the specifics of your questions:
1) Yes, you may buy clothing where are now to be worn after the Omer.
2) Yes, you may buy new shoes now, being that your current shoes are uncomfortable.
3) Not recommended to buy clothing items just because it’s more convenient.
4) Yes, the new clothing may be worn on Shabbos.
*Although not mentioned in Shulchan Aruch, this Minhag is rooted, as mentioned, in early Poskim, including the Leket Yosher – in the Minhagim of the Baal Terumas Hadeshen and Teshuvos U’Psokim Chachmei Ashkenaz – Siman 69.