ive anabled a port forward on port 80 (TCP/UDP) to my server, but i still cant acess it. i know its unsafe to just open a port like that, this is temporary, just wanna see if it works. ill put a reverse proxt and https on it later
Absolutely do not expose your server on port 80. Http is unencrypted, you'd be sending your login credentials in plaintext across the open internet. That is Very Bad™. If you own a domain name, you can set up a letsencypt cert fairly easily for free. Then you could expose 443 and at least your traffic will be encrypted in transit. It won't solve the other potential issues of exposing your instance like brute force or ddos attacks, but I'd consider it a bare minimum.
If you use a VPN like many others are suggesting it won't matter as much because the unencrypted traffic never leaves your local network.
As a side note: you not technically need a domain or a let's encrypt certificate to enable https. As a test you can create your own certificate, and use that for https (snake-oil certificate).
This is not appropriate for longer-term usage.
If you want to run websites on the Internet long-term, you should buy a domain and get a lets-encrypt certificate.