I would suggest some basic EDC items or basic utility thing that would be nice to have but you normally wouldn't spend money on.

Flashlights- https://www.amazon.com/dp/B078ZFJ3Z7/?coliid=I14KRBUUUCTDOC&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

Hand warmer- https://www.amazon.com/dp/B013HLGTUS/?coliid=I2PPV1KPI66UH2&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

Door stoppers if you travel.
https://www.amazon.com/dp/B06XVQN9W2/?coliid=IXHQN4C0UZIM6&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

Travel towels. https://www.amazon.com/dp/B07WMG6V5L/?coliid=I3TNYXNSJPCTCA&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

If you want to stick to cosplay and such maybe accessories for costumes or storage?

Heads for wigs. https://www.amazon.com/Wig-Mannequin-Head-Maniquins-Seamless/dp/B08T6DJ9XK/ref=mp_s_a_1_5?crid=314R2OGCB5BNA&keywords=maniquins+head+for+wig&qid=1636774427&sprefix=maniquins+head+f%2Caps%2C174&sr=8-5

Garment bags https://www.amazon.com/MARMINS-Dress-Gowns-Clear-Garment/dp/B08MYTXLZ6/ref=mp_s_a_1_1_sspa?crid=1KS13AIE3KMI1&keywords=travel+dress+garment+bag&qid=1636774548&sprefix=travel+dress+%2Caps%2C148&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFEUUNCNDhVR0NPOVomZW5jcnlwdGVkSWQ9QTA5NDI4OTMzQUFEUlNNRkQ4WURHJmVuY3J5cHRlZEFkSWQ9QTA2NTA2NDJZUktHOFU2S003Tkcmd2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

It won't necessarily stop entry but get a door wedge with an [alarm](3-pack upgraded door stop alarm -great for traveling security door stopper doorstop safety tools for home set of 3 https://www.amazon.com/dp/B06XVQN9W2/ref=cm_sw_r_cp_apa_i_gTl-Eb85JDQGH). They're pretty loud when they go off and would let know if your door is opened while you're in the bathroom or asleep.

Also, I don't know if it got mentioned but get locks for your windows. They also sell [alarms](ge personal security window/door, 4-pack, diy protection, burglar alert, wireless, chime/alarm, easy installation, ideal for home, garage, apartment, dorm, rv and office, 45174, 4 pack https://www.amazon.com/dp/B00FGPM1SS/ref=cm_sw_r_cp_apa_i_4Vl-EbXQQH7X1) that are made of two parts that go off when separated, so you put one on the window frame and one in the window itself, if someone opens/closes the window you will know.