There's absolutely nothing to excuse. Maybe I overlooked something in your original post, and maybe it was just my American background speaking up. For me, though, "new to guns," does not automatically mean "never handled a gun." Anyway, that's cleared up, now.
For shooting range, and HD, a full-sized gun will serve you well. Full-sized guns are easier to shoot, and easier to shoot well than smaller pistols, as a general rule. My comments on the P30L . . . . Unless I'm mistaken (and I'm always fine with being corrected if I am) is that the L already means it's a long-slide version. I've spent a lot of time on gun boards and one complaint that I don't think I've ever seen is, "That HK was just too small for me." HK makes good firearms, but in my opinion, they lean towards "overbuilt" and "large."
Let us know how the range session goes, and if you learn anything about what you like and don't like. That will help us help you.