Hi @Rajesh365
when you create Forms for the Portal, you have to opprtunity to add so called metadata to that forms. This metadata may include helptexts in all languages and for some datatypes the possibility to render them diffrently.
For example a lookup can be rendered as a drop down (good, when there are only a few choices) and bools can be rendered in diffrent ways and so on. Depends a little bit on your requirements.
You also have the possibility to use existing or create your own so called PCFs ( https://docs.microsoft.com/en-us/power-apps/developer/component-framework/overview ) , basically components. Currently, only field bound (and i think unbound, but i am not sure) controls are supported in Portals. But we created also some list like controls which we bound to a field. a little bit clumsy but does the job.
This is a really great feature as you can use the controls in many places.
So, basically you are completely free in the design/UI/UX of each and every field by using PCF
Hope this helps a little bit,
Christian
PS no need to excuse for questions, especially this is a good question
PPS I had a project last year, where we used a mix of forms and controls which were written by out own and used plain html/js/vue based things and used the webapi to store the data. This worked really well. Today i would go for the pcf approach (which wasn't available when starting the portal)